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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is known. The description adds useful behavioral context: 'sem credenciais' (no authentication), 'pague por consulta com crédito pré-pago' (cost side effect), and that data is public/official with LGPD responsibility on the client. No contradiction with annotations.

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 three sentences, front-loaded with the core purpose, then covering credentials/billing, and finally legal context. Each sentence adds information, though the third sentence about LGPD is somewhat tangential to tool selection/invocation. Overall it is tight 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?

For a simple read-only tool with 4 flat parameters and no output schema, the description covers purpose, access, cost, and data classification. However, it does not explain the 'completo' parameter or indicate what the returned data looks like, which are relevant gaps for an agent deciding whether this query satisfies the user's need.

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 0%, so the description must compensate, but it only mentions 'CPF e nome' which loosely maps to Cpf, Name, and Surname. The 'completo' boolean parameter is entirely unexplained, and no format or constraint details are provided. The description adds little beyond the parameter names already present in the schema.

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 opens with a clear verb-resource pair: 'Dados cadastrais de uma pessoa física no Brasil a partir do CPF e nome', stating exactly what the tool does. It distinguishes itself from the sibling tools (e.g., authenticate, connect, marketplace) by being the only one focused on Brazilian CPF/name cadastral lookup.

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 gives clear usage context: this is the tool for querying public cadastral data of a Brazilian individual via CPF and name, with no credentials and prepaid credit charges. It does not explicitly list exclusions or alternatives, but none of the sibling tools serve a similar purpose, so the context is sufficient.

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