validate_siret

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

Annotations already indicate readOnly and idempotent. The description adds behavioral context beyond annotations: mentions the Luhn algorithm, return fields, and automatic handling of the La Poste special case. No contradictions.

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?

Three focused sentences with no fluff. Front-loaded with the main purpose, then details on structure, return, and special case handling. Every sentence adds value.

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 tool's simplicity (single parameter) and the presence of an output schema, the description covers all necessary information: purpose, input format, output fields, and a special case. No gaps.

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?

The single parameter 'siret' has 100% schema coverage, but the description adds meaning beyond the schema by explaining the SIRET structure (SIREN + establishment) and providing an example with spaces/dashes.

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 clearly states the tool validates a French SIRET using the Luhn algorithm, explains its structure (SIREN + establishment), and lists the return fields. It is specific and distinct from sibling validation tools for other identifiers.

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?

The description implicitly indicates when to use this tool (when a SIRET number needs validation), but does not explicitly compare to alternatives or provide when-not usage. The sibling tools are for different identifier types, so the context is clear.

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