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

Annotations only cover safety and idempotency; the description adds the quota accounting semantics ('TOUT OU RIEN', nothing deducted on quota_exceeded), the error code, the batch_id resume path, the returned per-invoice state plus signed ZIP link, and a prompt-injection warning about untrusted invoice content. That is substantial disclosure beyond structured fields.

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?

Purpose and hard limits are front-loaded, and the untrusted-content warning is correctly placed at the end where it is not buried mid-sentence. The parenthetical 'mêmes règles que le lot du site' is the one soft spot — it references an external context the agent cannot verify.

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?

With annotations and an output schema present, the description covers what the output schema cannot: quota accounting rules, partial-failure semantics and resume. Only the error-recovery path beyond quota_exceeded (e.g. partial validation failures) is unstated.

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 75%, so the schema already documents most parameters. The description still adds meaning to two of them: the 20-item cap and 'lot' grouping for sources, and the resume behavior behind batch_id. accept_terms and idempotency_key are left to the schema alone.

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 opens with a specific verb and resource: 'Convertit jusqu'à 20 factures en un lot', and immediately bounds the scope with the quota rule. An agent can distinguish this from the single-invoice sibling convert_to_facturx by the explicit 'lot' framing, though that sibling is never named.

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?

It gives concrete operating conditions: all-or-nothing unlocking, quota limiting, spreadsheet splitting, and resume via { batch_id }. However, it never states when to prefer this over convert_to_facturx or create_upload_url, so the routing decision is left implicit.

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