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

Goes well beyond the annotations: discloses the POST route, the registre:write scope, that idempotency_key is sent as the Idempotency-Key header with 24 h retention and stored-answer replay on retry, required Bearer API key, and precise billing (0,99 $ per delivered document on live keys; test keys and 4xx/5xx free). The fail-closed behavior on a missing deed is exactly the kind of trait an agent needs and no annotation conveys.

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?

Every sentence carries real information (billing, auth, idempotency, fail-closed), but the full French restatement roughly doubles the length without adding facts, and leading with the raw route 'POST /v1/actes' is a weak front-load for an agent selecting a tool.

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 billed, authenticated, idempotent document-retrieval tool with no output schema, the description covers auth requirements, cost model, retry semantics, failure mode and availability limits. An agent has everything needed to call it correctly and predict charges.

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 baseline is 3; the description earns a bump by explaining the runtime meaning of idempotency_key (transmitted as the Idempotency-Key header, retained 24 h, retry returns the stored answer), which the schema's 'unique key for this write' does not. Nothing is added about registration_number or circonscription formatting beyond the schema.

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 PDF of one deed identified by registration number and circonscription foncière. It is distinguishable from document_get and plan_get by naming the deed artifact explicitly, though it never names those siblings to contrast with them.

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?

Gives clear usage context: works when Fonciq holds the deed (no Registre fee), fails closed when the deed is missing, and notes that the structured deed analysis is 'Bientôt' and not offered here — effectively a when-not-to-use clause. It does not point at any sibling tool as the alternative for a missing deed or for other document types.

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