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

Annotations declare readOnlyHint=true, openWorldHint=false and idempotentHint=false; the description goes beyond them by explaining the randomness/seed contract ('omitida, o servidor sorteia uma e a devolve') and the error semantics for type-inapplicable options. That is real behavioral context, though it does not discuss volume/rate considerations or what a partial failure across 'quantidade' documents looks like.

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 tight sentences, front-loaded with the action and count range, then the type list, then the constraint/error rule and the seed return. Every sentence carries new information and nothing is padded.

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 values need not be enumerated, and the description still adds the non-obvious seed-return fact. For a 15-parameter tool with full schema coverage and clear annotations, the type/option interaction and error behavior are the only real gaps an agent would face, and both are covered.

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 already 100%, so the baseline is 3. The description adds value by summarizing the cross-parameter constraint matrix (uf only for cpf, alfanumerico only for cnpj, bandeira only for cartao, banco only for conta, size/character rules only for senha) and by declaring that a mismatched option is an error rather than being ignored.

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 precise verb+resource+scope: generates 1 to 100 valid documents of one of five enumerated types (cpf, cnpj, cartao, conta, senha), and adds a differentiating guarantee that check digits are computed rather than fabricated. It never names a sibling, so an agent gets no help distinguishing it from the 'gerar' or 'validar_documento' tools from the text 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?

Usage guidance is implied through the per-type option matrix ('cada tipo aceita só as suas opções') and the explicit error rule for mismatched options, which tells an agent how to combine parameters. However, there is no statement of when to choose this tool over the sibling 'gerar' or 'validar_documento', and no prerequisites are described.

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