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

Annotations cover the safety profile (readOnly, idempotent, non-destructive), and the description adds value beyond that: default ordering (newest first), the fields returned (motion/amendment moved, Content/Not Content totals, winning side, government win/defeat), the upstream source, and a cost of 1 credit. The credit cost in particular is operational context no annotation provides.

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?

Front-loaded with the core action and scope, with the escape hatch to lords_division_result and the credit cost placed at the end where they belong. The middle sentence is a dense field list, but every listed field is informative rather than filler.

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 no output schema, the description takes on the job of describing return contents and does so explicitly, plus ordering, source, and cost. For a two-parameter read-only search tool, an agent has everything needed to call it and interpret the result.

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 both q and take are already documented, and the description only restates that searching is by keyword. It does not explain take limits or truncation behavior, so it adds little beyond the schema — the expected baseline of 3 applies.

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 ('Find House of Lords votes (divisions)'), the query mode ('by keyword, newest first'), and the exact shape of the answer it returns. It is cleanly separable from commons_division_search (Commons) and lords_division_result (peer-level detail) without opening either schema.

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 a concrete question it answers ('did the Lords defeat the government on X?') and explicitly routes to lords_division_result when peer names are needed. It stops short of stating when NOT to use it (e.g. Commons divisions, or when a specific division ID is already known), so it is strong but not fully exhaustive.

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