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

Annotations declare readOnlyHint: true, and the description's verb 'Consulta' aligns with this. The description adds minimal behavioral context beyond the annotation—it specifies the document types and the reference field but does not disclose response structure, potential statuses, or any operational nuances. With the annotation covering safety, the added value is marginal, so a 3 is appropriate.

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 a single, front-loaded sentence that conveys essential information without redundancy. It is appropriately concise and well-structured, fitting comfortably within quality limits.

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 (one required parameter, no output schema), the description provides sufficient context to know when and how to invoke it. It identifies the resource, the reference method, and document types. A small gap exists: it does not describe the return format or possible statuses, but for a simple status query this is not critical. Overall, it is complete enough for correct invocation.

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% for both parameters. The description reinforces the meaning of 'referencia' by specifying it as a Focus NFe reference and listing document types, but this adds little beyond what the schema already states (e.g., 'Referência Focus NFe do documento'). Since the schema carries the weight, a baseline of 3 is appropriate.

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 action ('consulta o status de processamento'), the resource ('documento fiscal'), and narrows the scope to specific document types (NFS-e, NF-e, NFC-e) and a specific lookup method ('pela referência Focus NFe'). This is a specific verb+resource combination that distinguishes it from siblings like emitir_nfse or cancelar_nfse.

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 implies the use case: querying the processing status of a fiscal document by its unique Focus NFe reference. It provides clear context but does not explicitly mention when not to use it or suggest alternatives (e.g., listar_documentos_fiscais for broader listing). No exclusionary guidance is given, so it falls short of a 5.

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