Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint, idempotentHint, non-destructive and closed-world, so the safety profile is covered. The description adds real behavioral context beyond that: jurisdiction restriction to England, that output is guidance rather than legal advice, and critically that it does not create or serve a notice — an important expectation to set for a landlord-facing workflow.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Two sentences, no filler. The capability statement comes first and the usage/scoping caveats follow, so the agent gets the what before the when-not. Every clause carries information.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With an output schema present and annotations covering safety, the description does not need to explain return values, and it appropriately spends its words on jurisdiction, disclaimers and non-action. The only shortfall is the unresolved tension between the England-only scope and the country parameter that accepts scotland/wales.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so every parameter including rent_due_date anchoring and the optional proposed_start_date is already documented in structured form. The description adds no additional parameter meaning, so the baseline of 3 applies. It also leaves unaddressed why the country parameter enumerates scotland and wales while the tool is stated as England only.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description names a specific verb and resource chain: calculating the earliest permissible start date and latest service date for a Section 13 (Form 4A) rent increase for an assured periodic tenancy in England. It is concrete enough that an agent cannot confuse it with the sibling get_eligibility_requirements, and the two outputs it produces are stated up front.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

It gives explicit triggers (landlord asking about raising rent, Section 13 notice periods, Form 4A timing, when an increase can take effect) plus boundaries (England only, general guidance not legal advice, does not create or serve a notice). The one gap is that it never names or routes to the sibling tool get_eligibility_requirements as an alternative.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.