Submit to FACe (Spain B2G)

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

Annotations indicate readOnlyHint=false, which matches the write nature of submission. The description adds behavioral details beyond annotations: it specifies network calls (except mock), mode-dependent behavior, and required recipient structure. No contradictions found.

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 description is well-structured with a clear primary action, bullet-pointed modes, and bilingual content. It is front-loaded with the essential purpose. Slight redundancy due to full Spanish translation, but overall concise and informative.

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?

Given the tool's simplicity (2 parameters, output schema exists), the description adequately explains input requirements, modes, and expected output. It does not cover error handling or authentication, but these are reasonable omissions for a focused submission tool. Completeness is strong for the context.

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% with both parameters described. The description adds semantic value by explaining the mode options (mock, sandbox, production) and their implications, as well as the required DIR3 codes context for the invoice. This goes beyond the schema's basic parameter descriptions.

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 identifies the tool's specific function: submitting a Facturae invoice to the Spanish FACe B2G portal. It details the required recipient format (DIR3 codes) and return value (registro), and distinguishes from sibling face_status which polls for status.

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 states when to use the tool (to submit invoices) and mentions three modes (mock, sandbox, production) with clear environment guidance. It implies prerequisites (DIR3 codes) and references face_status for subsequent polling, providing good contextual guidance without explicitly stating when not to use.

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