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

Goes well beyond the annotations: it discloses that OCR is not triggered ('Não inicia OCR'), that automatic reading only occurs on analysis request, the 201 status, explicit size/volume limits (JSON 11.2 MB, PDF 8 MiB, 20 docs/80 MiB/50 pages per company), and that identical files are reused. This is exactly the kind of behavioral context annotations (readOnly=false, idempotent=false, destructive=false) cannot convey.

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?

Purpose is front-loaded in the first sentence, followed by tightly packed constraints. The telegraphic style (bare numbers, '201') is dense but each clause carries distinct, non-redundant information, so little is wasted.

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 mutating, non-idempotent upload with no output schema, the description covers prerequisites, limits, dedup behavior, and OCR timing. It only lightly touches the response (a bare '201'), which is acceptable given no output schema exists.

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%, so the baseline is 3, but the description adds meaningful limits tied to the payload (PDF up to 8 MiB) and per-company quota constraints not present in the schema. It does not explain the 'tipo' enum values beyond the schema, but the added size/volume semantics lift it above baseline.

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?

States a specific verb (envia/anexar) and resource (comprovante PDF da empresa), making the action clear. It does not, however, differentiate itself from siblings like documento_arquivos, documentos_empresa, or documento_vincular, so an agent must infer the boundary from the name alone.

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?

Gives clear operational context: 'Sessão necessária' states a prerequisite and 'prefira HTTP para arquivos grandes' points to an alternative transport for large files. It stops short of naming alternative tools or stating when-not to use this one, so it is context rather than full routing guidance.

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