Get a company by SIREN

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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so the safety profile is covered. The description adds real value by listing what the response contains (legal form, VAT, dates, head office, leaders, revenue), which compensates for the absent output schema; it does not cover auth or not-found behavior.

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?

One sentence, front-loaded with the verb, the resource, and the identifier, with the payload enumeration trailing behind. No filler or redundancy.

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?

For a single-parameter read with no output schema, the return-field enumeration covers most of what an agent needs to decide and interpret. Missing only edge-case behavior such as what happens when the SIREN does not resolve.

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 single parameter is fully documented with a pattern and example. The description's '9-digit SIREN' restates the schema constraint without adding format, validation, or fallback guidance, so 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 and resource ('Fetch one French company') plus the key identifier (9-digit SIREN) and enumerates the returned data. The singular 'one ... company' implicitly contrasts with the sibling search_company, but no sibling is named 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?

Usage is only implied: the agent can infer this is the lookup to use when it already holds a SIREN rather than search criteria. There is no explicit when-to-use statement, no prerequisites, and no named alternative for cases where the SIREN is unknown.

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