population_par_commune

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

Annotations already indicate read-only, safe, idempotent. Description adds that it returns a discriminated LookupResult and explains behavior when commune has merged/changed code, providing additional transparency beyond annotations.

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?

Concise paragraph that front-loads key information (returns population for commune by code), includes source and error handling. Could be slightly more structured but is efficient.

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?

Given the simple tool (one parameter, output schema exists), the description covers purpose, source, return structure, error behavior, and a reference to a sibling tool, making it fully self-contained for an agent.

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 coverage is 100%, and the parameter description already contains examples. The tool description does not add further semantics for the single parameter.

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?

Description clearly states it returns population data for a French commune by INSEE code, specifying the exact measures (PMUN, PCAP, PTOT) and source. It differentiates from sibling 'autocomplete_commune' by noting orientation when commune code is not found, and from 'get_commune_by_code' by focusing on population specifically.

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?

Provides clear context for when to use (get population of a commune) and handles the not-found case by directing to 'autocomplete_commune'. However, it does not explicitly compare with other population tools like 'population_par_departement' or give a when-not-to-use scenario.

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