List French communes

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

Annotations already cover the safety profile (readOnlyHint=true, destructiveHint=false, openWorldHint=true). The description goes further by disclosing the upstream source and the returned fields (INSEE code, postcodes, département, région, population), plus the at-least-one-filter rule. No rate limits or error behavior, but that is a minor gap given annotation coverage.

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 lookup keys and return contract are front-loaded ahead of the invocation constraint. 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 no output schema, the description takes on the burden of stating what comes back and does so explicitly. It also conveys the mandatory-filter requirement, leaving nothing an agent needs to call it correctly.

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 name, postcode, departement and limit are already documented with patterns and examples. The description restates the three filter keys but adds no format or constraint detail beyond the schema, so the baseline 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 ('look up'), a precise resource ('French communes'), names the three lookup keys, and cites the data source (geo.api.gouv.fr). This is clearly distinguishable from address geocoding (search_address) and company lookups in the sibling set.

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?

'Give at least one filter' adds a real usage constraint that the schema does not enforce (required parameters = 0), telling the agent how to invoke it correctly. However, it names no alternatives or when-not conditions relative to search_address or reverse_geocode.

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