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

There are no annotations, so the description carries the full burden. It discloses the legal scope, acceptable inputs, the B2C exception, the 'format only' behavior, and the cost/payment rail ($0.01 USDC Base x402). This is solid behavioral disclosure for a simple formatter.

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?

A single dense sentence packs purpose, scope, fields, exceptions, and pricing without wasted words. The most important identifying info is front-loaded, and every clause 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?

For a zero-parameter formatting tool with no output schema, the description sufficiently covers input expectations, scope, and cost. The only minor gap is not describing the exact return format, but that is not essential for selecting and invoking this tool.

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?

With zero declared parameters and an empty schema, the description becomes the only source of input semantics. It specifies 'client name + optional SIRET/SIREN + city' and the B2C SIRET omission rule, which meaningfully tells the agent what information to provide.

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 names a specific action, 'buyer identification', a resource, 'French invoice', and even cites the legal basis L441-9. The explicit list of expected fields and the 'Format only' qualifier make it clear this is a formatting/identification helper, not a validation tool like check_siret.

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 context is clearly a French invoice buyer block, and the B2C guidance ('B2C may omit SIRET') gives a concrete condition for when different input is acceptable. 'Format only' implies not to be used for validation, though it does not explicitly name alternative sibling tools.

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