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

With no annotations, the description carries the full burden and does well: it discloses the caching model, the exact cost ($0.0004 on registry miss), the upstream source (INPI), and both auth paths (Bearer balance or x402). It omits failure modes — what happens if payment fails or the document does not exist — and whether the returned URL expires.

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 dense sentences, zero filler, front-loaded with what is returned before the cost/auth details. Every clause adds information an agent needs.

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 6-parameter read tool with full schema coverage and no output schema, the description explains the return value (a URL) and the payment mechanics, which are the non-obvious parts. It stops short of describing error behavior or URL lifetime, which an agent would need before relying on the link.

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 the schema already documents every parameter's meaning, valid patterns, and the kind enum with per-value notes. The description's parenthetical '(statutes, decisions, annual accounts)' merely restates the enum rather than adding selection guidance such as which parameters are required per kind.

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 — returns the URL of a PDF — and enumerates the document classes covered (statutes, decisions, annual accounts). This is clearly distinguishable from siblings like get_company or search_companies, which return company data rather than document links.

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 implies the tool is for retrieving document PDFs but never states when to use it versus alternatives, nor the prerequisite chain (e.g., obtain id/siren from get_company first, then request acte vs comptes). Usage is inferable from the kind enum but not guided.

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