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

Annotations already declare the mutation/non-idempotent/open-world profile, so the description only needs to add scope, which it does with 'aucun accès à un compte existant ni aux données métier'. It does not say what happens on an invalid or expired code, whether the signup is consumed or the code single-use, or any rate limiting — meaningful gaps for a non-idempotent verification call.

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 short sentences, front-loaded with the action and followed by the scope exclusion; no filler. It is efficient, though it is brief enough that the brevity reflects thin content rather than tight editing.

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 state-changing, non-idempotent, open-world tool with no output schema and zero parameter descriptions, the definition is too thin. It does not describe the success/failure outcome, what verification unlocks, or what the agent should do next, which is information the agent cannot get from structured fields.

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 0%, so the description carries full burden, yet it only clarifies that 'code' is the one received by e-mail. The 'signup_id' parameter, its origin, and the 8-character fixed length of the code are left entirely to the schema's constraints with no semantic explanation.

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?

Names a specific verb and resource ('Vérifie le code reçu par e-mail pour cette inscription'), so the agent knows this is signup code verification rather than account creation. It implicitly separates itself from complete_account_signup by scoping to the code check, but never names the sibling 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 implied by 'pour cette inscription' and by the exclusion of existing-account and business-data access, which narrows the context. However, there is no explicit statement of when to call this versus complete_account_signup or start_account_signup, and no prerequisite that a signup_id must already exist.

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