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

Behavioral context goes well beyond annotations: it discloses paid consumption with prepaid credits, absence of platform credentials, official-source nature, non-confidential status, and LGPD accountability. This is meaningful additional context on top of readOnlyHint/idempotentHint.

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 compact and front-loaded with the core purpose, followed by payment and legal context. Each sentence contributes meaningfully, though the LGPD sentence, while relevant, adds context rather than operational guidance.

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 high parameter count, zero schema coverage, and absence of an output schema, the description is incomplete. It does not explain how parameters should be populated, what constitutes a valid response, or which optional fields are required under different consultation modes.

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?

Input schema description coverage is 0% and the description does not explain any of the 9 parameters, including the 3 required ones (cpf, registro, codigo_seguranca). It also fails to clarify the authentication-related optional parameters (login_cpf/login_senha, pkcs12_cert/pkcs12_pass), leaving the agent without guidance on which parameters to use in which scenario.

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?

Description clearly identifies the tool as a CNH validation/consultation against official SENATRAN sources, using an explicit verb and resource. The scope ('Validar CNH') differentiates it from generic sibling tools like connect or marketplace.

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 context of use is clear: the tool is for querying CNH data from official Brazilian sources. There are no explicit exclusion statements or alternative tool recommendations, but no sibling performs a similar function, so a 'when to use' guidance is already sufficient; only the 'when not to use' part is missing.

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