facture_facturx

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

With no annotations provided, the description carries the full disclosure burden and does add meaningful context: the POST endpoint implies a document-creating side effect, the output composition (PDF/A-3 + XML EN 16931) is explicit, and format=preview's 'PDF sans XML' variant is stated. However, it does not disclose whether the document is persisted or transmitted to the e-invoicing platform, whether EN 16931 conformance is validated, or what error behavior looks like — notable gaps for a compliance-critical mutation.

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?

Four dense sentences with zero filler, front-loaded with the usage trigger before the format, endpoint, and payload-shape details. Every sentence contributes distinct information — trigger condition, output format, endpoint, required structure, and format variation — with no redundancy.

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 an 8-parameter tool with nested objects, no annotations, and no output schema, the description covers the invocation essentials (when, format, required structure) and the schema covers all parameters at 100%. However, with no output schema, the description should explain return values and validation/error behavior for a compliance-critical document tool; it does neither, and the schema's enum-versus-description mismatch for the 'format' parameter is only partially resolved.

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%, setting the baseline at 3, but the description adds genuine value beyond the schema: it names the exact required fields of lines[] (description, quantity, unit_price HT, vat_rate) and clarifies format=preview as 'PDF sans XML'. This clarification matters because the schema's own format description cites values ('pdf', 'xml') that do not exist in the actual enum ['facturx', 'preview'], so the description helps resolve a confusing 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?

The description names a specific deliverable — 'Facture Factur-X (PDF/A-3 + XML EN 16931)' — and ties it to French e-invoicing reform compliance (EN 16931), which clearly separates it from invoice-adjacent siblings like relance_facture_client, devis_travaux, and quittance_loyer. The verb is implicit rather than stated (POST /api/v1/documents/facturx implies generation) and no sibling is named, so it stops short of a 5.

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 description opens with an explicit trigger condition — 'QUAND une facture doit être conforme à la facturation électronique française (réforme e-facture, EN 16931)' — telling the agent precisely when to select this tool over others. It provides clear usage context but names no exclusions or alternative tools, so the when-not-to-use guidance is missing.

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