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

Annotations provide readOnlyHint=true, and the description adds substantial behavioral context beyond that: the ordered result set, null meaning 'donnée non publiée', the anonymous-access limitation for individual enterprises, and quota cost. It also discloses the exact fields returned, giving the agent a realistic picture of the tool's behavior without contradicting the 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?

The description is front-loaded with the main purpose, then proceeds through fields, null behavior, an example, a key access limitation, and cost. Every sentence adds distinct information and there is no filler or repetition of schema content.

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 present, the description compensates by enumerating the returned fields and explicitly stating that null means the data is not published. It also covers ordering, anonymous limitations, and quota cost. An agent has enough information to call the tool correctly and interpret its response.

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%, so the parameter semantics already come from the schema: siren has a pattern and examples, and limite has default, minimum, and maximum. The description adds a concrete example object and clarifies null handling, but does not need to explain parameter meanings further. Baseline 3 is appropriate.

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 opens with a specific verb and resource: 'Renvoie les derniers comptes annuels déposés d'une société française (SIREN)', and adds the ordering 'du plus récent au plus ancien'. This clearly separates it from sibling tools like propecto_societe or propecto_rechercher_societes, which concern company identity or search rather than annual financial statements.

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 provides useful operational context, such as 'Sans clé API (entrée anonyme), les entreprises individuelles ne sont pas servies' and 'Coût : 1 unité de quota', but it never explicitly states when to prefer this tool over sibling alternatives or when not to use it. The intended use is clear by implication from the financial-statement domain, but no explicit routing is given.

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