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

Annotations declare readOnlyHint=false, openWorldHint=true, destructiveHint=false, which is not self-explanatory for a PDF fetch. The description adds real context: it preserves access controls and existing download limits, and is scoped to the credential-determined store. It does not explain what 'readOnlyHint=false' means here (e.g., session consumption), so it is good but not complete.

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 sentences, front-loaded with the core action, then the exclusion, then the behavioral note. Every sentence carries distinct information with no filler.

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?

With an output schema present, return-value explanation is unnecessary, and the description covers scope, exclusion, and access behavior. The remaining gap is the unresolved overlap with get_label_pdf, which an agent must disambiguate to choose correctly.

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 only 50%: instanceId is documented in the schema as ignored, but supportCode has no description. The description only obliquely ties supportCode to a 'pré-postagem confirmada' and adds no format or lookup semantics beyond the schema, so it does not fully compensate for the gap.

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 and resource ('Recupera apenas o PDF de uma pré-postagem confirmada') plus a scope constraint (authenticated store's attempt). However, it does not differentiate from the sibling get_label_pdf, which appears to retrieve the same artifact, leaving the agent to guess which one to call.

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?

Explicitly carves out the negative case: 'Não cria etiqueta nem refaz emissão' tells the agent not to use this for issuing or reissuing a label. It stops short of naming the alternative tool (generate_label) for those cases, but the boundary is clearly drawn.

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