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

Annotations already declare readOnly, idempotent, non-destructive and closed-world behavior, so the safety profile is covered. The description adds genuinely new context the annotations cannot convey: England-only scope and an explicit 'general guidance, not legal advice' caveat, which matters for how an agent frames the answer.

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?

Three short sentences, each earning its place: the first names the resource and its scope, the second gives usage triggers, the third bounds jurisdiction and liability. The most decision-relevant content (what it lists) is front-loaded.

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?

For a zero-parameter, read-only lookup with an output schema and rich annotations, nothing an agent needs to select or call it correctly is missing. Return-value structure is left to the output schema, and scope plus the legal-advice caveat are stated.

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?

The tool takes zero parameters, so there is no parameter meaning to convey and the baseline of 4 applies. The description correctly avoids inventing inputs and the empty schema matches the described parameterless lookup.

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?

States a specific verb and resource (list eligibility requirements) tied to a named instrument (Section 13 notice, Form 4A), a tenancy type (assured periodic) and a jurisdiction (England). An agent can tell this is a static rules-lookup tool, distinct from the sibling calculate_notice_dates which computes dates.

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?

Gives three explicit trigger questions (can I use Section 13, what are the rent-increase rules, what is Form 4A), which is clear when-to-use guidance. It does not explicitly exclude or route to the sibling calculate_notice_dates, so an agent must infer that boundary.

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