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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, so the description doesn't contradict them. The description adds context: it is a paid service with prepaid credit, hosted by the platform, and the data is not confidential. However, it doesn't disclose potential rate limits, response format, or what exactly happens on a successful or failed query. Given annotations cover the safety profile, a 3 is appropriate; description adds some context but not deep behavioral detail.

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 a single sentence with a clear structure, approximately 40 words. It covers purpose, hosting, payment, and a legal note. It's efficient but could be slightly more front-loaded with parameter clarification. Overall, it's concise and each clause adds value.

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 there is no output schema and no parameter descriptions in the schema, the description should provide more context about the parameters and perhaps the response. It does explain the nature of the data (not confidential, same as available to citizens) and the payment requirement. However, without parameter guidance and potential output explanations, completeness is moderate. The tool's complexity is low with only two parameters, so a 3 is reasonable.

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 two parameters, 'cpf' and 'cnpj', both strings, with no description in the schema (0% coverage). The description does not explain the parameters at all. It implies that the certificate can be queried for a person (CPF) or company (CNPJ), but it never explicitly states which parameter corresponds to which. This is a significant gap as the description fails to compensate for the lack of schema documentation.

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 purpose: it queries the official source for a 'Certidão Negativa de Feitos' (negative certificate of legal proceedings) from the Brazilian Public Ministry (MPT-PB). It uses specific verb 'consultar' and names the resource. Although it doesn't explicitly distinguish from sibling tools, which are unrelated platform utilities, the context is clear enough.

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 mentions that it is hosted by the platform, requires prepaid credit, and queries official Brazilian sources, implying it's for obtaining citizen-available data. However, it does not explicitly state when to use this tool vs alternatives, nor does it mention exclusions (e.g., not for sensitive data). Siblings are generic tools, so this tool stands out, but explicit usage guidance is limited.

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