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

Annotations already establish read-only, idempotent, closed-world behavior, and the description adds genuinely new operational facts: page size of 50, code order as the default, that filters combine, and that identifiers may be codes or slugs. It does not mention total counts or a max-page cap, but the paging behavior is disclosed.

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 rhetorical opening ("Which commune has the most or the least of something is one call here") and the re-explanation of count-ranking rules consume space already spent in the schema's sort field. Reorganizing it into a short "what it does / how to filter / how to sort" structure would carry the same content in fewer sentences.

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, return values need no explanation, and the description covers what matters for correct invocation: filter dimensions, combinability, sort syntax, default ordering, and pagination. Only edge details (page bounds, total result handling) are absent, which is acceptable against the structured fields.

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% and the schema's own sort description already documents the minus prefix, 2014./change. prefixes, and the per1000 ranking subtlety, so the description's long sort passage is largely a restatement. The notes that filters combine and that code or slug is accepted are marginal additions over the schema, keeping this at the baseline.

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 makes the verb+resource concrete: it returns every commune matching a filter, ordered by any figure, and it frames the primary use case (finding the largest/smallest place in one call). It implicitly contrasts with one-by-one lookup (get_commune) but never names a sibling, so differentiation from search/get_unit is left to the agent.

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?

Clear context is given: use this to rank communes by any indicator or establishment count, and "With no filter it lists every commune, so sort: \"-population\" alone gives the largest in the country" supplies a concrete invocation pattern. It stops short of explicit when-not-to-use guidance or naming alternatives like search.

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