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

With no annotations, the description carries the full burden and does a good job: it discloses that the tool returns a url_paiement to hand to a human rather than granting credits directly, that credits land only on confirmed payment (asynchronous), and that the call is free. It omits auth/permission requirements and failure behavior, keeping it short of a 5.

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?

Three compact clauses, front-loaded with the core action, followed by the return/timing and cost. Every sentence carries distinct, non-redundant information.

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 one-parameter tool with no output schema, the description supplies the key missing context: the returned url_paiement, the human hand-off, and the deferred credit timing. Only minor gaps remain (permissions, error/edge behavior), so it is nearly complete.

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 param is fully enumerated, so the baseline is 3. The description merely repeats the tier/quantity mapping already present in the schema ('essentiel 100, pro 500 ou volume 2 000 chiffrages'), adding no new parameter meaning.

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: 'Crée une page de paiement par carte pour recharger la clé' — creates a card payment page to top up the key. This is unmistakably distinct from the calculation/quote siblings, and it even names the tiers. An agent can identify what it does without opening the schema.

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 rather than stated: the agent can infer it should call this when the key needs recharging, and the description explains the downstream flow (give url_paiement to the human). But there is no explicit when-to-use, when-not, or named alternative among the siblings.

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