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

Annotations already cover safety (readOnlyHint, idempotentHint, destructiveHint). The description adds behavioral context by specifying it returns download links (not the content itself) and that files are usually PDFs. This is useful beyond the annotations, though it doesn't detail error cases or pagination—acceptable given the simple retrieval nature.

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 two sentences, front-loaded with the tool's function and key output (links). It avoids redundancy and mentions only essential details, making it highly concise and well-structured.

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 (a retrieval of download links) and the combination of annotations plus description, it is fairly complete. It clarifies the output type (links) and the intended use case. However, it could hint at the response structure (e.g., a list of documents), but that's minor. No output schema exists, so some return details are missing, but not critical.

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?

The schema has no descriptions (0% coverage), so the description must explain parameters. It does so by stating they are 'cnpj+ano+sequencial (a referência devolvida pela pncp_buscar)', which connects them to a known reference. It doesn't detail formats, but the explanation is sufficient for an agent to understand they are a compound key from another tool.

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 tool retrieves documents of a bidding process with download links, and explicitly mentions the input format (cnpj+ano+sequencial) and its relationship to pncp_buscar. It distinguishes itself from siblings with its specific focus on document retrieval, not search or details.

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 provides direct usage guidance: 'Use pra trazer o PDF do edital pro usuário ou pra outra IA ler o conteúdo.' It also establishes the prerequisite that the reference comes from pncp_buscar, which implies when this tool is appropriate. While it doesn't state exclusions, the context is clear enough for an agent to decide.

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