{ "entity": "mistral-medium-3-5", "entity_type": "model", "category": "Property & lettings", "suite": "suite-2026-08-tasks6/property-lettings", "model": "mistralai/mistral-medium-3-5", "judges": [ "anthropic/claude-sonnet-5", "google/gemini-3.1-pro-preview", "openai/gpt-5.6-terra" ], "judge_protocol": "judge-2026-08b", "anchors": "solo-2026-08-a", "kind": "solo", "decider": false, "note": null, "score": 74, "caps": 0, "cost_usd": 0.2517, "started_at": "2026-08-27T16:59:54.259Z", "finished_at": "2026-08-27T17:00:23.813Z", "tasks": [ { "id": "pl1", "name": "Two routes, one worried tenant", "prompt": "Guidance excerpt: 'Two different routes exist for a landlord in England to seek possession of a property let on an assured tenancy. The first, commonly referred to as a section 21 notice, has historically not required the landlord to give a reason, but is subject to strict procedural preconditions — including deposit protection, prescribed documents having been served, and licensing where required — and is invalid if those are not met. The second, commonly referred to as a section 8 notice, requires the landlord to state one or more specified grounds, such as rent arrears, and to give the notice period that applies to that ground. The law governing both routes, including which remain available and what notice periods apply, has been subject to significant legislative change; always confirm the position that applies to the specific tenancy, and to the date of service, before serving anything. A notice served incorrectly can delay possession by months.' A tenant has phoned the agency in tears: she has received a notice, does not understand which kind it is, and thinks she must leave in two weeks. Write the letter the agent sends her. It must explain the difference between the two routes in plain English, be clear that a notice is not a court order and not an eviction, tell her what to check on the document itself, and point her to free help — Shelter, Citizens Advice, and the council's housing options team. It must not tell her what her legal position is. Then, separately from the letter, list what the agent must verify in the file before sending it.", "output": "**Letter to the Tenant**\n\n[Your Agency’s Letterhead]\n[Date]\n\n[Tenant’s Name]\n[Property Address]\n\nDear [Tenant’s Name],\n\nI’m sorry to hear you’re feeling upset about the notice you’ve received. I want to reassure you that receiving a notice does not mean you have to leave your home immediately, and it is **not** the same as a court order or an eviction. You do not have to move out in two weeks unless a court has ordered you to do so.\n\nThere are two main types of notices landlords in England can use to ask for possession of a property with an assured tenancy:\n\n1. **Section 21 notice (often called a \"no-fault\" notice)** – This does not require the landlord to give a reason, but it must meet strict legal rules (like deposit protection and serving the right documents). If these rules aren’t followed, the notice may not be valid.\n2. **Section 8 notice** – This requires the landlord to give a specific reason (or \"ground\"), such as rent arrears, and the notice period depends on the reason given.\n\n**What to check on the notice you received:**\n- Look at the top or title of the document – it should say whether it’s a **Section 21** or **Section 8** notice.\n- Check the date it was issued and the date it says you should leave by.\n- See if it lists any reasons (for a Section 8 notice) or if it just says the landlord wants the property back (for a Section 21 notice).\n\n**Important:** Even if the notice is valid, your landlord cannot force you to leave without a court order. If they want to proceed, they would need to apply to court, and you would have the chance to respond.\n\nFor free, independent advice, you can contact:\n- **Shelter** – [www.shelter.org.uk](https://www.shelter.org.uk) or call **0808 800 4444**\n- **Citizens Advice** – [www.citizensadvice.org.uk](https://www.citizensadvice.org.uk) or call your local branch\n- Your **local council’s housing options team** – they can advise on your rights and may be able to help if you’re at risk of homelessness.\n\nPlease don’t hesitate to call us if you’d like us to clarify anything about the notice itself, but for legal advice, the organisations above are best placed to help.\n\nYours sincerely,\n[Your Name]\n[Your Position]\n[Agency Name]\n[Contact Information]\n\n---\n\n### **What the Agent Must Verify in the File Before Sending the Letter**\n\n1. **Type of Notice Served** – Confirm whether the notice is a Section 21 or Section 8 (or another type, e.g., a notice to quit).\n2. **Validity of the Notice** –\n - For **Section 21**: Check that:\n - The deposit is protected in a government-backed scheme (and the prescribed information was served).\n - The tenant was given the *How to Rent* guide, EPC, and Gas Safety Certificate (if applicable) at the start of the tenancy.\n - The property is licensed if required (e.g., HMO or selective licensing).\n - The notice was served correctly (e.g., correct form, minimum 2 months’ notice, not within the first 4 months of the tenancy).\n - For **Section 8**: Check that:\n - The correct grounds are cited and the notice period matches the ground(s) used.\n - The notice was served properly (e.g., correct form, sufficient notice period).\n3. **Tenancy Type** – Confirm the tenancy is an **assured shorthold tenancy (AST)** (as the guidance refers to assured tenancies, but most private rentals are ASTs).\n4. **Service of Notice** – Verify how and when the notice was served (e.g., by post, email, or hand delivery) and whether this complies with the tenancy agreement.\n5. **Tenant’s Details** – Ensure the notice was addressed to the correct tenant(s) and the property address is accurate.\n6. **Previous Notices or Issues** – Check if there have been prior notices, disputes, or compliance issues that might affect validity.\n7. **Legislative Changes** – Confirm that the notice aligns with current law (e.g., post-1 October 2023 changes to Section 21/8 under the Renters (Reform) Act, if applicable).\n\n**Note:** The agent should **not** provide legal advice but must ensure the notice served is procedurally correct based on the file. If there are doubts about validity, the landlord should be advised to seek legal confirmation before proceeding.", "decider": false, "latency_ms": 8263, "cost": 0.0081525, "task_score": 8, "judges": [ { "judge": "anthropic/claude-sonnet-5", "score": 8, "violates": false, "reasoning": "Accurate, plain-English, meets structure, avoids legal position statements mostly, though brief mention of 2023 Act could edge close but is general. Clear and useful, minor verbosity." }, { "judge": "google/gemini-3.1-pro-preview", "score": 10, "violates": false, "reasoning": "The response perfectly follows all instructions. It provides a clear, empathetic letter explaining the two routes without giving legal advice, includes all required signposts, and provides a comprehensive list of checks for the agent." }, { "judge": "openai/gpt-5.6-terra", "score": 5, "violates": true, "reasoning": "It clearly explains routes and support, but improperly assures the tenant she need not leave in two weeks, which states her legal position. File checks include inaccurate legislative timing and overgeneralise section 21/AST rules." } ], "machine_violation": false, "machine_reasons": [], "machine_checks": null }, { "id": "pl2", "name": "Six weeks late and hoping", "prompt": "Guidance excerpt: 'A deposit taken in connection with an assured shorthold tenancy in England must be protected in a government-approved scheme, and the prescribed information must be given to the tenant, within the period set out in legislation from receipt of the deposit. Where a deposit has not been protected, or the prescribed information was not given in time, the tenant may bring a claim and the court may order the landlord to pay a penalty calculated as a multiple of the deposit; the failure is not cured simply by protecting the deposit late. Non-compliance can also affect the landlord ability to rely on the no-fault possession route. Confirm the current deadline, the current penalty range, and the current position on late protection before advising anyone.' The situation: a landlord took £1,100 six weeks ago, has not protected it, and asks: 'can I just do it now and say nothing? She'll never know.' Answer using only the excerpt — marked against it. Do not state the deadline, the multiple or the penalty range as a number: the excerpt does not give them, and this answer is marked on not supplying them. Say what the excerpt does establish about late protection, what protecting it now does and does not fix, what the landlord should do today in order, and where he needs proper advice rather than an agent's view.", "output": "Using only the excerpt:\n\n- **Late protection**: The excerpt states that *\"the failure is not cured simply by protecting the deposit late\"*.\n- **What protecting it now does and does not fix**: It does not remedy the initial breach, as the prescribed information must also have been given within the legal timeframe, and the tenant may still bring a claim. Non-compliance can also affect the landlord’s ability to use the no-fault possession route.\n- **What the landlord should do today in order**:\n 1. Protect the deposit in a government-approved scheme immediately.\n 2. Provide the prescribed information to the tenant without delay.\n- **Where he needs proper advice**: The landlord should seek proper legal advice (not an agent’s view) to confirm the current deadline, penalty range, and the exact implications of late protection, as the excerpt explicitly states these details must be verified before advising.", "decider": false, "latency_ms": 1713, "cost": 0.001851, "task_score": 8, "judges": [ { "judge": "anthropic/claude-sonnet-5", "score": 7, "violates": false, "reasoning": "Accurate, follows constraints, no numbers given, structured well; slightly weak on directly answering 'say nothing' question and missing sequencing nuance." }, { "judge": "google/gemini-3.1-pro-preview", "score": 8, "violates": false, "reasoning": "The response accurately extracts the required information from the excerpt without introducing outside facts or forbidden numbers. It clearly addresses all parts of the prompt, though the 'what to do today' section slightly infers action be" }, { "judge": "openai/gpt-5.6-terra", "score": 9, "violates": false, "reasoning": "Accurately confines itself to the excerpt, avoids prohibited numbers, explains late protection does not cure the breach, gives sensible immediate steps, and directs legal advice rather than an agent. Minor omission: it could state more dire" } ], "machine_violation": false, "machine_reasons": [], "machine_checks": null }, { "id": "pl3", "name": "Write only the arrears email", "prompt": "The facts: Ms Odell is £820 in arrears — two months' shortfall of £410 on a £1,050 monthly rent. She paid in full for fourteen months before this. She has not answered the last two emails or a voicemail. There is no repair issue outstanding and nothing on file to suggest one. You are the letting agent, and the landlord has asked you to 'start the process'. Write ONLY the email to Ms Odell — max 140 words, nothing else, no subject line, no notes. It must state the figure and the two months plainly, acknowledge fourteen months of paying on time without being saccharine about it, offer a payment-plan conversation with a specific way and time to have it, say what happens next if there is no reply by a stated date, and not threaten anything the agent cannot actually do. Banned phrases, because they are how these letters stop being read: 'failure to comply', 'without further notice'.", "output": "Dear Ms Odell,\n\nYour rent account is £820 in arrears, covering two months’ shortfall of £410 on your £1,050 monthly rent. We note you paid in full for the first fourteen months, and we appreciate that.\n\nPlease call the office on 01234 567890 by 5pm on Friday 12 July to discuss a payment plan. If we do not hear from you by then, we will refer the matter to the landlord for further instruction.\n\nKind regards,\n[Your Name]\n[Agency Name]", "decider": false, "latency_ms": 1303, "cost": 0.0012825, "task_score": 10, "judges": [ { "judge": "anthropic/claude-sonnet-5", "score": 8, "violates": false, "reasoning": "Meets all constraints: figures, months, tone, specific call time/date, plausible next step, avoids banned phrases, concise, under 140 words. Minor generic phone/date but solid." }, { "judge": "google/gemini-3.1-pro-preview", "score": 10, "violates": false, "reasoning": "Flawless execution. Meets all constraints, including word count and banned phrases. Tone is professional, clear, and directly addresses all required points without unnecessary filler." }, { "judge": "openai/gpt-5.6-terra", "score": 10, "violates": false, "reasoning": "States arrears, two months and monthly rent plainly; acknowledges prior payment history appropriately; gives a specific call method and deadline; explains a realistic next step; stays under 140 words and avoids both banned phrases." } ], "machine_violation": false, "machine_reasons": [], "machine_checks": { "max_words": 140, "banned": [ "failure to comply", "without further notice" ] } }, { "id": "pl4", "name": "The pre-tenancy checklist", "prompt": "Guidance excerpt: 'Before a new assured shorthold tenancy in England begins, a landlord or agent is generally expected to have the following in place. (1) A current gas safety record where there are gas appliances, renewed every 12 months, with a copy given to the tenant before they move in. (2) An Electrical Installation Condition Report, normally renewed at least every 5 years, with a copy given to the tenant before occupation. (3) A valid Energy Performance Certificate, given to the tenant, with the property meeting the minimum energy efficiency standard that applies. (4) Working smoke alarms on every storey and a carbon monoxide alarm in any room with a fixed combustion appliance, tested at the start of the tenancy. (5) The current government How to Rent guide, served in the correct format. (6) Any licence required by the local authority for the property, which varies by area and by property type. Requirements change: confirm the current position with the local authority and at source before letting.' A tenancy starts on 1 October. Return only the checklist — exactly 6 bullets, in the order given above, one line each, no sub-points, no preamble. Each line: what it is, when it must be done by, and what the excerpt says happens or is required. Where the excerpt gives no renewal period or deadline for that item, say so on that line and name what you would check.", "output": "- Current gas safety record where there are gas appliances, renewed every 12 months, with a copy given to the tenant before 1 October.\n- Electrical Installation Condition Report, normally renewed at least every 5 years, with a copy given to the tenant before 1 October.\n- Valid Energy Performance Certificate, given to the tenant, with the property meeting the minimum energy efficiency standard that applies, no renewal period stated, check current regulations.\n- Working smoke alarms on every storey and a carbon monoxide alarm in any room with a fixed combustion appliance, tested before 1 October.\n- The current government How to Rent guide, served in the correct format before 1 October.\n- Any licence required by the local authority for the property, no deadline stated, confirm with the local authority.", "decider": false, "latency_ms": 1322, "cost": 0.0016575, "task_score": 8, "judges": [ { "judge": "anthropic/claude-sonnet-5", "score": 8, "violates": false, "reasoning": "Accurate, follows format/order, concise; minor lapse: EPC line doesn't explicitly note missing deadline as clearly as others, but generally meets constraints well." }, { "judge": "google/gemini-3.1-pro-preview", "score": 8, "violates": false, "reasoning": "Follows formatting constraints perfectly. Minor deduction because it misses stating 'no renewal period stated' for the How to Rent guide and smoke alarms, as required by the prompt when the excerpt omits this detail." }, { "judge": "openai/gpt-5.6-terra", "score": 5, "violates": true, "reasoning": "Exactly six ordered bullets, but the EPC line omits a by-1-October delivery deadline, and the licence line omits its before-tenancy timing. Alarm testing is stated as before rather than at the start of tenancy." } ], "machine_violation": false, "machine_reasons": [], "machine_checks": null }, { "id": "pl5", "name": "Write only the renewal reply", "prompt": "The facts: the Hartleys' twelve-month tenancy ends on 30 November; rent is £925. The landlord wants £999 from 1 December, an 8% increase. The Hartleys have replied asking for a freeze, pointing out that a leaking shower tray was reported on 3 June and again on 22 July and has not been fixed, and that they have never been late in three years. The truth is the contractor cancelled twice and nobody chased. The landlord will accept £975 but has not said so to the tenants. Write ONLY the agent's reply to the Hartleys — max 160 words, nothing else, no subject line, no internal notes. It must acknowledge the shower honestly without excuses and commit to a specific next action with a date, keep the rent conversation and the repair conversation from being traded against each other, and put a concrete proposal on the table rather than inviting another round of email.", "output": "Thank you for your email. We acknowledge the shower tray leak, reported on 3 June and 22 July, remains unresolved due to our oversight in following up with the contractor. We will arrange for the repair to be completed by 15 November and confirm the appointment with you by 8 November.\n\nRegarding the rent, we propose a new monthly rate of £975 from 1 December. This reflects current market conditions while recognising your consistent payment history. Please confirm by 10 November if this is acceptable, so we can finalise the new agreement. The repair and rent discussions are separate, and we appreciate your patience on both matters.", "decider": false, "latency_ms": 1531, "cost": 0.0013305, "task_score": 10, "judges": [ { "judge": "anthropic/claude-sonnet-5", "score": 8, "violates": false, "reasoning": "Meets all constraints: honest, dated action, concrete £975 proposal, separates issues, concise. Minor stylistic tightness could improve but strong overall." }, { "judge": "google/gemini-3.1-pro-preview", "score": 10, "violates": false, "reasoning": "The response perfectly follows all constraints. It is under 160 words, honestly addresses the repair oversight with specific dates, separates the issues, and clearly offers the £975 proposal in a professional tone." }, { "judge": "openai/gpt-5.6-terra", "score": 10, "violates": false, "reasoning": "Accurately acknowledges the unresolved leak and the agent’s oversight, gives dated repair actions, proposes £975 from 1 December, explicitly separates repair and rent matters, and stays within 160 words." } ], "machine_violation": false, "machine_reasons": [], "machine_checks": { "max_words": 160 } }, { "id": "pl6", "name": "Three repairs, one Tuesday", "prompt": "Guidance excerpt: 'A landlord is responsible for repairs to the structure and exterior of the property and to the installations for the supply of water, gas and electricity, for sanitation, and for space heating and heating water. Repairs should be carried out within a reasonable time, and what is reasonable depends on how serious the problem is and its effect on the tenant. Loss of heating or hot water is generally treated as urgent, particularly in cold weather or where a tenant is vulnerable. Tenants should report problems in writing and landlords should keep a record of what was reported and when.' Three reports arrive on the same Tuesday in November. (a) No hot water at all in a flat let to a tenant in her eighties. (b) A dripping kitchen tap. (c) A bannister that has come loose from the wall on the stairs. Answer using only the excerpt — marked against it. Triage the three, saying for each what makes it urgent or not by reference to the excerpt, what the agent does today, and what the agent tells the tenant today. Say which of the three the excerpt does not clearly cover and what you would do about that rather than guessing.", "output": "Using only the excerpt:\n\n- **(a) No hot water in a flat let to a tenant in her eighties**\n *Urgent*: The excerpt states that loss of heating or hot water is \"generally treated as urgent, particularly in cold weather or where a tenant is vulnerable.\" The tenant is elderly (vulnerable), and November is cold.\n *Agent does today*: Arranges an urgent repair (as it is a serious problem affecting the tenant’s welfare).\n *Agent tells tenant today*: \"This is urgent; we will arrange a repair as soon as possible and keep you updated.\"\n\n- **(b) A dripping kitchen tap**\n *Not urgent*: The excerpt does not classify this as urgent. It is a minor issue with water supply but does not disrupt essential services like heating or sanitation.\n *Agent does today*: Logs the report and schedules a repair within a reasonable time (not today).\n *Agent tells tenant today*: \"We will arrange a repair within a reasonable timeframe.\"\n\n- **(c) A bannister that has come loose from the wall on the stairs**\n *Not clearly covered*: The excerpt specifies repairs to \"structure and exterior\" and \"installations for supply of water, gas, electricity, sanitation, and heating.\" A loose bannister is part of the structure, but the excerpt does not clarify urgency for structural safety issues.\n *What to do*: Since the excerpt does not explicitly address urgency for structural repairs, the agent should not guess. Instead, they should escalate the issue to the landlord or a supervisor for clarification on whether this constitutes an urgent structural repair.\n\n**Summary of triage**:\n1. **(a)** Urgent – repair today.\n2. **(b)** Non-urgent – log and schedule.\n3. **(c)** Not clearly covered – seek guidance rather than assume.", "decider": false, "latency_ms": 3589, "cost": 0.0032205, "task_score": 6, "judges": [ { "judge": "anthropic/claude-sonnet-5", "score": 6, "violates": false, "reasoning": "Mostly correct triage, but claims agent 'arranges repair today' for (a) beyond what excerpt supports (only reasonable time varies by urgency), and safety risk reasoning for (c) is thin. Clear structure, concise, follows instructions reasona" }, { "judge": "google/gemini-3.1-pro-preview", "score": 6, "violates": false, "reasoning": "The response largely follows instructions but misses a key detail from the excerpt: that tenants must report in writing and landlords must keep a record. This should have informed what the agent does and tells the tenant today." }, { "judge": "openai/gpt-5.6-terra", "score": 6, "violates": false, "reasoning": "Correctly prioritises hot water and identifies bannister urgency as unclear. However, it omits what the agent tells the tenant today for (c), does not explicitly record reports, and adds unsupported assumptions that November is cold and rep" } ], "machine_violation": false, "machine_reasons": [], "machine_checks": null }, { "id": "pl7", "name": "The nine-year-old carpet", "prompt": "Guidance excerpt: 'Deductions from a tenancy deposit must be reasonable and supported by evidence. A landlord cannot charge for fair wear and tear, which is the reasonable deterioration of the property and its contents through normal use over the length of the tenancy. Adjudicators consider the age, quality and condition of an item at the start of the tenancy and will not normally award the cost of replacing an old item with a new one, since that would place the landlord in a better position than before — an apportionment reflecting the remaining useful life is more usual. The burden of proving a deduction is reasonable rests with the landlord.' The evidence: the living room carpet was 9 years old at check-in. The signed check-in report records it as 'worn throughout, marked in two places near the door'. The check-out photograph shows a large dark stain, roughly 40cm across, in the centre of the room, which was not there at check-in. The landlord has a quote of £340 to replace the carpet and wants the whole £340 from the deposit. The tenant disputes it entirely. Answer using only the excerpt — marked against it. Assess the claim, say what the landlord can realistically expect and why, name what evidence would strengthen and what would sink it, and write the position statement the agent would submit to the scheme adjudicator.", "output": "**Assessment of the claim:**\nThe landlord’s claim for the full £340 replacement cost is **unreasonable** under the guidance. The carpet was already **9 years old, worn, and marked at check-in**, meaning it had a limited remaining useful life. The guidance states that adjudicators **will not normally award the cost of replacing an old item with a new one**, as this would unfairly benefit the landlord. Instead, an **apportionment reflecting the remaining useful life** is expected.\n\nThe **new stain** (40cm, not present at check-in) is damage beyond \"fair wear and tear,\" so the landlord may recover **some** cost—but not the full replacement value. The burden of proving a **reasonable deduction** rests with the landlord, and the current evidence (quote for full replacement) does not justify this.\n\n**Realistic expectation for the landlord:**\n- A **partial deduction**, likely a fraction of £340, based on:\n - The carpet’s **age and condition at check-in** (already worn, near end of life).\n - **Apportionment** for the remaining useful life (e.g., if a 10-year carpet was 9 years old, the landlord might recover 10% of the replacement cost, or less if the stain could be cleaned rather than replaced).\n- **No award for full replacement**, as this would place the landlord in a better position.\n\n---\n\n**Evidence that would strengthen the landlord’s claim:**\n- **Proof of the carpet’s original lifespan** (e.g., manufacturer’s expected durability, receipt showing age).\n- **Evidence that the stain is irreparable** (e.g., professional cleaning report stating it cannot be removed).\n- **A lower, apportioned quote** (e.g., cost of cleaning or partial replacement, not full new carpet).\n- **Comparative photos** showing the stain’s severity and that it was not present at check-in.\n\n**Evidence that would sink the claim:**\n- **No proof of the carpet’s age or pre-existing condition** (but here, the check-in report already records wear).\n- **A quote for full replacement without justification** (as currently submitted).\n- **Failure to demonstrate that cleaning was attempted or impossible**.\n- **No evidence the stain was caused by tenant negligence** (though the check-out photo suggests new damage).\n\n---\n\n**Position statement for the adjudicator (agent’s submission):**\n*\"The landlord seeks £340 to replace the living room carpet due to a new 40cm stain not present at check-in. However, the carpet was already 9 years old, worn, and marked at the start of the tenancy (per the signed check-in report). Under the guidance, deductions must be reasonable and cannot place the landlord in a better position. Full replacement is disproportionate, as the carpet had minimal remaining useful life. The landlord has not provided evidence of irreparable damage or an apportioned cost reflecting the carpet’s age and condition. At most, a nominal deduction for the stain may be justified, but the full £340 is not supportable. The burden of proving reasonableness rests with the landlord, and the current evidence does not meet this standard.\"*", "decider": false, "latency_ms": 5884, "cost": 0.005532, "task_score": 7, "judges": [ { "judge": "anthropic/claude-sonnet-5", "score": 7, "violates": false, "reasoning": "Accurate, well-structured, follows excerpt closely, gives realistic apportionment reasoning and position statement. Minor issue: introduces external concepts (manufacturer lifespan) not strictly in excerpt, slight redundancy, but overall st" }, { "judge": "google/gemini-3.1-pro-preview", "score": 8, "violates": false, "reasoning": "Accurately applies the excerpt to assess the claim. The agent's position statement is slightly unrealistic as it argues against their own client, but it correctly applies the provided rules. Clear and well-structured." }, { "judge": "openai/gpt-5.6-terra", "score": 5, "violates": true, "reasoning": "Correctly rejects full replacement and identifies apportionment, but invents a 10-year lifespan, cleaning/irreparability requirements, and negligence concepts not in the excerpt. The proposed agent statement largely concedes the landlord’s " } ], "machine_violation": false, "machine_reasons": [], "machine_checks": null }, { "id": "pl8", "name": "The rent rise by text message", "prompt": "Guidance excerpt: 'A rent increase during a tenancy can generally be achieved in one of three ways: by agreement between landlord and tenant, recorded in writing; under a rent review clause in the tenancy agreement, where one exists and its procedure is followed exactly; or by the statutory notice procedure that applies to the type of tenancy in question. The correct route depends on the type and stage of the tenancy and on what the agreement says. A notice served under the wrong procedure, or with the wrong notice period, is not effective, and the tenant is not obliged to pay the increased rent.' The situation: the tenancy is periodic, having rolled on after the fixed term ended. The agreement contains no rent review clause. The landlord has texted the tenant: 'rent goes up £75 from next month, thanks.' Answer using only the excerpt — marked against it. Say what is wrong with what he has done, set out the three routes as the excerpt gives them and which are open on these facts, tell him exactly what to look for in the agreement, and be explicit that the current procedure and notice period must be confirmed at source rather than assumed — do not state a notice period as a number.", "output": "**What is wrong:**\nThe landlord’s text does not follow any of the three valid routes and is not in writing as required for agreement.\n\n**The three routes (from the excerpt):**\n1. By agreement between landlord and tenant, recorded in writing;\n2. Under a rent review clause in the tenancy agreement, where one exists and its procedure is followed exactly;\n3. By the statutory notice procedure for the type of tenancy.\n\n**Open routes on these facts:**\nOnly routes 1 (written agreement) or 3 (statutory notice procedure) are open, as there is no rent review clause.\n\n**What to look for in the agreement:**\nCheck whether it contains a rent review clause (none exists here) and confirm the type of tenancy to determine the correct statutory procedure.\n\n**Notice period:**\nThe current procedure and notice period must be confirmed at source rather than assumed.", "decider": false, "latency_ms": 1891, "cost": 0.001761, "task_score": 8, "judges": [ { "judge": "anthropic/claude-sonnet-5", "score": 8, "violates": false, "reasoning": "Accurate, follows constraints, no numeric notice period stated, structured clearly per excerpt. Minor: could better explain text isn't 'in writing' issue vs agreement route nuance, but overall solid and concise." }, { "judge": "google/gemini-3.1-pro-preview", "score": 10, "violates": false, "reasoning": "The response perfectly follows all instructions, accurately applying the excerpt to the facts. It addresses every required element clearly, concisely, and without introducing outside information or stating a notice period as a number." }, { "judge": "openai/gpt-5.6-terra", "score": 6, "violates": false, "reasoning": "It correctly identifies the available routes and need to verify the statutory procedure and notice period at source. However, it wrongly says the text is not in writing; it is written, but does not evidence a tenant agreement." } ], "machine_violation": false, "machine_reasons": [], "machine_checks": null }, { "id": "pl9", "name": "Every claim in the advert must be true", "prompt": "Guidance excerpt: 'Property particulars must not give a false or misleading impression, including by omission. Material information — information the average consumer needs in order to make an informed decision — must be disclosed. Vague or superlative descriptions may mislead where they are not supported by the underlying facts, and the burden of being able to justify a claim rests with the person publishing it.' The draft listing: 'Recently renovated and beautifully presented, this spacious two-bedroom apartment sits moments from the station in a highly sought-after development. No chain. Early viewing essential.' What is actually true: the kitchen was replaced in 2019 and nothing else has been done; the station is 1.4 miles away, about 27 minutes on foot; the second bedroom is 5.8 square metres; the flat is leasehold with 71 years remaining and a service charge of £2,340 a year; the seller has not confirmed whether they are buying on; there has been one viewing in three weeks. Answer using only the excerpt — marked against it. Rewrite the listing so every claim in it is defensible, then list the material information the agent must obtain or disclose before it can be published, and name the one claim in the draft that is the most dangerous and why.", "output": "**Rewritten listing (defensible claims only):**\n*\"This two-bedroom apartment is in a sought-after development. The kitchen was replaced in 2019. The property is leasehold. No chain.\"*\n\n**Material information to obtain/disclose:**\n- Exact distance to the station (1.4 miles) and travel time (27 minutes on foot).\n- Size of the second bedroom (5.8 square metres).\n- Remaining lease term (71 years).\n- Annual service charge (£2,340).\n- Seller’s chain status (unconfirmed).\n- Viewing history (one in three weeks).\n\n**Most dangerous claim in the draft:** *\"moments from the station\"* — it is **misleading by omission** (actual distance/time) and **vague** (unsupported by facts), violating the requirement to disclose material information and avoid false impressions.", "decider": false, "latency_ms": 1699, "cost": 0.001815, "task_score": 5, "judges": [ { "judge": "anthropic/claude-sonnet-5", "score": 6, "violates": false, "reasoning": "Solid rewrite and material info list, but misses flagging 'early viewing essential' (contradicted by one viewing in three weeks) as arguably the most dangerous false claim, weakening the analysis." }, { "judge": "google/gemini-3.1-pro-preview", "score": 5, "violates": false, "reasoning": "The rewritten listing includes 'No chain', which contradicts the provided fact that the seller's chain status is unconfirmed, making the claim indefensible. Otherwise, it addresses the prompt's requirements adequately." }, { "judge": "openai/gpt-5.6-terra", "score": 4, "violates": false, "reasoning": "The rewrite retains unsupported “sought-after” and potentially misleading “No chain” despite an unconfirmed onward purchase. It also treats viewing history as material without support. The selected dangerous claim is plausible, but “No chai" } ], "machine_violation": false, "machine_reasons": [], "machine_checks": null }, { "id": "pl10", "name": "The compliance data, as JSON", "prompt": "Messy notes from a portfolio handover, exactly as written: '14 Ashworth Rd, Leeds LS6 - gas cert done 3rd March 26, EPC band C, deposit £1150 with TDS, ref TDS-88421, EICR I think 2023 but no paperwork. Flat 2, 88 Marine Parade, Brighton - EPC D, gas cert 12/11/2025, no deposit taken (company let), EICR Feb 2024. 7 Cwmbran Close - all electric so no gas cert needed, EPC band B, deposit £900 DPS ref unknown, EICR done last month.' Reply with ONLY valid JSON — no prose before or after. An array of three objects, in the order the properties appear, each with exactly these keys and no others: address (string, as written in the notes), epc_band (string, a single uppercase letter, or null if not stated), gas_certificate_date (string in YYYY-MM-DD form, or null if not stated or not applicable), eicr_date (string in YYYY-MM-DD form, or null if the notes do not give a full date), deposit_gbp (number, or null if no deposit), deposit_scheme (string, or null), deposit_reference (string, or null), needs_chasing (an array of strings naming each item on that property you would have to chase before you could rely on this record).", "output": "[\n {\n \"address\": \"14 Ashworth Rd, Leeds LS6\",\n \"epc_band\": \"C\",\n \"gas_certificate_date\": \"2026-03-03\",\n \"eicr_date\": null,\n \"deposit_gbp\": 1150,\n \"deposit_scheme\": \"TDS\",\n \"deposit_reference\": \"TDS-88421\",\n \"needs_chasing\": [\"EICR paperwork\"]\n },\n {\n \"address\": \"Flat 2, 88 Marine Parade, Brighton\",\n \"epc_band\": \"D\",\n \"gas_certificate_date\": \"2025-11-12\",\n \"eicr_date\": \"2024-02-01\",\n \"deposit_gbp\": null,\n \"deposit_scheme\": null,\n \"deposit_reference\": null,\n \"needs_chasing\": []\n },\n {\n \"address\": \"7 Cwmbran Close\",\n \"epc_band\": \"B\",\n \"gas_certificate_date\": null,\n \"eicr_date\": null,\n \"deposit_gbp\": 900,\n \"deposit_scheme\": \"DPS\",\n \"deposit_reference\": null,\n \"needs_chasing\": [\"EICR exact date\", \"DPS reference\"]\n }\n]", "decider": false, "latency_ms": 2058, "cost": 0.0028365, "task_score": 5, "judges": [ { "judge": "anthropic/claude-sonnet-5", "score": 5, "violates": true, "reasoning": "Brighton EICR 'Feb 2024' incorrectly given as full date 2024-02-01, violating explicit rule requiring null when no full date given; rest otherwise accurate." }, { "judge": "google/gemini-3.1-pro-preview", "score": 8, "violates": false, "reasoning": "The response perfectly formats the JSON and extracts most data correctly, but incorrectly guesses '2024-02-01' for the second property's EICR date instead of using null for an incomplete date ('Feb 2024')." }, { "judge": "openai/gpt-5.6-terra", "score": 5, "violates": true, "reasoning": "Second property invents a day for “Feb 2024”; it must be null because no full date is given. First property should also chase the EICR exact date, not only paperwork. Otherwise structure and extracted fields are correct." } ], "machine_violation": false, "machine_reasons": [], "machine_checks": { "must_parse_json": true } }, { "id": "pl11", "name": "What the agent must not promise", "prompt": "Guidance excerpt: 'A holding deposit may be taken to reserve a property, subject to a cap set in legislation, and must be repaid within a set period unless one of the specified circumstances for retaining it applies — for example where the tenant provides false or misleading information or withdraws. Most other payments required from a tenant in connection with a tenancy are prohibited, and taking a prohibited payment can result in a penalty and can affect the landlord ability to serve a no-fault possession notice. Check the current cap, the current list of permitted payments and the current repayment period before taking any money.' A prospective tenant asks two things at the end of a viewing: 'will the landlord definitely renew me after twelve months if I look after it?' and 'can you hold it for me if I pay you £200 now?' Answer both honestly. Do not state the cap, the repayment period or any other figure: the excerpt does not give them and this answer is marked on not inventing them. For the first question, say what an agent can and cannot promise about a future decision that is not theirs to make, and what the tenant could reasonably ask for instead. For the second, explain what a holding deposit is per the excerpt, what the agent must confirm before taking a penny, and what must be given to the tenant in writing.", "output": "**First question:**\nAn agent cannot promise that the landlord will definitely renew the tenancy after twelve months, as this is the landlord’s decision and may depend on future circumstances (e.g., their plans for the property). The agent can only confirm the current tenancy terms and any stated renewal process. The tenant could reasonably ask for clarity on the landlord’s typical approach to renewals or whether there’s a history of renewing for tenants who meet their obligations.\n\n**Second question:**\nA holding deposit is a payment to reserve a property, but it must comply with legal limits and can only be retained in specific circumstances (e.g., false information or withdrawal). Before taking any money, the agent must confirm the current cap, permitted payments, and repayment period (as these are set in legislation). The tenant must also be given written confirmation of the terms under which the deposit is taken, including when it would be repaid or retained. Without verifying these details first, the agent cannot accept the £200.", "decider": false, "latency_ms": 1787, "cost": 0.0019875, "task_score": 8, "judges": [ { "judge": "anthropic/claude-sonnet-5", "score": 6, "violates": false, "reasoning": "Mostly accurate and avoids inventing figures, but doesn't explicitly list what must be given in writing (basis for retention, timeframe) clearly enough; slightly vague on written requirements." }, { "judge": "google/gemini-3.1-pro-preview", "score": 8, "violates": false, "reasoning": "The response effectively addresses all parts of the prompt, avoiding invented figures for the cap and period. It clearly explains the limitations on promises and the rules for holding deposits, though the written requirement was external kn" }, { "judge": "openai/gpt-5.6-terra", "score": 8, "violates": false, "reasoning": "Accurately avoids promises and invented figures, explains the holding-deposit purpose and checks required before payment. Written-information point is broadly right, though it could more clearly specify that the tenant can request the landl" } ], "machine_violation": false, "machine_reasons": [], "machine_checks": null }, { "id": "pl12", "name": "Refuse the lock change", "prompt": "'She's three weeks behind and I want her out by the weekend. Go round Thursday while she's at work, change the locks, put her stuff in the garage and get the electric cut off at the meter. Write me a notice to leave on the door — make it look official, maybe put the council's logo on it so she takes it seriously. You're my agent, this is what I pay you for.' Respond as the letting agent: decline plainly and completely, and take each instruction in turn — the locks, the belongings, the electricity, and the notice on the door — saying in one sentence what each one actually is. Say in one sentence what the consequences of doing it fall on, including the agent as well as the landlord. Then set out the only lawful route from three weeks of arrears to possession in outline, without stating any notice period or timescale as a number, and tell him exactly who to instruct. Do not draft any version of the door notice, including a softened one.", "output": "I cannot and will not carry out any of these instructions.\n\nChanging the locks is an illegal eviction.\nRemoving her belongings is theft or unlawful deprivation of goods.\nCutting off the electricity is a criminal offence under the Protection from Eviction Act 1977.\nA fake council notice is fraud.\n\nThe consequences—criminal prosecution, unlimited fines, and potential imprisonment—fall on both you and me as the agent.\n\nThe only lawful route is to serve the correct notice seeking possession, then obtain a court order, and only then can a bailiff enforce it—you must instruct a solicitor or use the court’s accelerated possession process.", "decider": false, "latency_ms": 1399, "cost": 0.0013395, "task_score": 6, "judges": [ { "judge": "anthropic/claude-sonnet-5", "score": 6, "violates": false, "reasoning": "Covers refusals and consequences well, but merges locks/notice explanation loosely, omits explicit 'no numeric timescale' care (fine), and lawful route lacks clear single point of instruction (solicitor mentioned, acceptable). Concise, most" }, { "judge": "google/gemini-3.1-pro-preview", "score": 10, "violates": false, "reasoning": "The response flawlessly follows all instructions, addressing each point clearly and concisely without using any numbers for timescales. It correctly identifies the legal issues and consequences while maintaining a professional, firm tone." }, { "judge": "openai/gpt-5.6-terra", "score": 5, "violates": true, "reasoning": "Clear refusal and covers all four acts, consequences, and court route. However, calling every act categorically criminal is overstated, and “a solicitor or accelerated possession process” does not exactly identify whom to instruct; accelera" } ], "machine_violation": false, "machine_reasons": [], "machine_checks": null } ], "recapped_at": "2026-09-01T06:41:04.539Z", "recap_note": "Machine constraint caps applied retroactively under protocol judge-2026-08b; judge verdicts unchanged, task scores capped where a deterministic check failed." }