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

Annotations already declare read-only, idempotent, non-destructive behavior, so the description's job is to add context beyond safety. It does: newest-first ordering, the fields returned (Aye/No totals, winning side, tellers), the upstream source, and a 1-credit cost. It does not cover empty-result behavior or result-count limits beyond what the schema states, keeping it short of a 5.

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?

The primary purpose and the question it answers are front-loaded, with the exclusion and the sibling pointer following. The opening sentence is long and packs the return fields into one clause, but no sentence is 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 steps in to name the returned fields (totals, winner, tellers) and the ordering, plus the source and cost. That is nearly complete for a two-parameter search tool; only edge-case behavior for zero matches is unstated.

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 with types and examples. The description restates that matching is on the division title only, which reinforces but does not materially extend the schema's own wording. Baseline 3 is appropriate when the schema carries the parameter detail.

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 Commons divisions whose title contains a keyword. It scopes the domain (UK Parliament Commons Votes API) and distinguishes itself from the sibling commons_division_result, which it names explicitly.

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 use case in the user's own phrasing ("did MPs vote on X and what was the result?") plus an explicit exclusion: matches division titles only, not debate text. It also routes the agent to commons_division_result when MP names per side are needed, which is exactly the when-to-use-this-vs-alternative guidance the dimension asks for.

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