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

Annotations declare readOnlyHint=true, destructiveHint=false, and idempotentHint=true, which align with the description of a query-only operation. The description adds value by disclosing that it requires prepaid credits, is hosted by the platform, and clarifies data privacy aspects (not confidential data, LGPD responsibilities). This goes beyond the annotations without contradicting them.

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, dense paragraph but efficiently conveys the tool's purpose, data source, payment model, and legal compliance. It's a bit long but each sentence carries meaningful information. Could be more structured with line breaks, but it's far from verbose.

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 (two optional string params, no output schema, read-only), the description covers the essential context: what it does, where it gets data, commercial terms (prepaid), and legal framing. The main gap is not specifying if at least one parameter is required and lack of behaviour when neither is provided, but this is minor for an agent.

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. While it doesn't explain 'cpf' or 'cnpj' individually, it clearly indicates the tool is for consulting 'Certidão Negativa' using CPF/CNPJ (which are standard Brazilian identifiers). The parameter names themselves are self-explanatory and the description provides sufficient context for an agent to infer their usage. Could have been more explicit about whether at least one is required (required params: 0).

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 'Certidão Negativa de Feitos' (Negative Certificate of Court Records) and its purpose: to consult official sources for CPF/CNPJ data. It also differentiates itself by mentioning it is hosted on their platform, requires prepaid credits, and addresses LGPD compliance, which uniquely positions it among siblings like 'authenticate' or 'connect'.

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 explains when to use this tool: for consulting data from official Brazilian sources, emphasizing it's the same non-confidential info available to citizens, and that the client is the data controller. It does not explicitly name alternative tools, but given the sibling list (authenticate, connect, etc.), the usage context is clear. Lacks explicit 'do not use if...' but covers the main use case.

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