Submit to FACe (Spain B2G)

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

Annotations indicate non-readonly and non-idempotent, consistent with a submission action. The description adds that it returns a submission reference for later polling with face_status. However, it lacks details on duplicate behavior or error scenarios.

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?

The English description is three sentences, each with distinct information: purpose, prerequisite, modes/return. No wasted words; front-loaded with main action.

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?

Covers purpose, prerequisite, modes, and return. Does not detail Facturae format or error handling, but given the presence of an output schema (not shown), it is sufficiently complete for a submission tool.

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?

Both parameters are fully described in the schema (100% coverage). The description reinforces the mode options but adds little beyond what the schema already provides.

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 clearly states the tool submits Facturae invoices to the Spanish FACe B2G portal. It specifies the action (submit), the resource (invoice), and the target (FACe portal). The distinction from sibling tool face_status (which polls status) is apparent.

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 explains modes (mock, sandbox, production) and their use cases, including that mock is for dev/test. It also states prerequisite DIR3 codes in the invoice. It does not explicitly say when not to use, but the context is clear enough.

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