es__sign_facturae_xades

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

With no annotations, the description carries the full burden and does it well: it reveals the two-step human-in-the-loop behavior, the PKCS#12 certificate source, SHA-256+RSA algorithm, and default policy. It omits minor details like whether the operation is local/remote or what exactly gets returned, but the explicit confirmation flow is a significant disclosure beyond the schema.

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 short paragraphs are front-loaded with purpose, then technical specifics, then the crucial human-in-the-loop workflow. No repetitive or filler sentences; the all-caps HITL line is easy to spot and highly actionable.

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 5-parameter signing tool with an output schema, the description is nearly complete: it covers the workflow, algorithm, and default policy. It doesn't explicitly state prerequisites like the AEAT_CERTIFICATE_PASSWORD environment variable or behavior when cert_path is null, but those are documented in the input schema, so the gap is minor.

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%, so the baseline is 3; the description adds value by explaining the confirmation_token lifecycle and by connecting cert_path to the password-from-environment constraint. It reinforces the default signature policy and ties it to the algorithm, which complements the schema rather than repeating it.

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 states a specific action ('Aplica una firma digital XAdES-EPES') on a clear resource ('documento Facturae XML'), and distinguishes it from sibling generation/validation/submission tools by its signing focus. It also names the exact standard and algorithm, leaving no ambiguity about what the tool does.

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 gives clear procedural context: call without confirmation_token to get a summary/token, then call with it to apply the real signature. It doesn't explicitly name alternatives or say 'use after generate_facturae_xml', but the signing purpose is evident from the first sentence and the sibling set.

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