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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false. The description adds valuable behavior context: it is hosted by the platform, requires prepaid credits, does not require platform credentials, returns citizen-available official data, and places LGPD compliance responsibility on the client. This is meaningful additional transparency beyond annotations and does not contradict 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 front-loads the purpose in the first sentence and is reasonably concise. It adds relevant legal and commercial context without excessive verbosity. It is slightly dense, but every sentence adds information about how the service works, cost, and compliance.

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?

Despite having 8 parameters and no output schema, the description does not explain the expected return value, the exact result of 'Imprimir CRLV-e', or how the credential parameters relate to the official system. It covers commercial and legal context well but leaves functional invocation details, including success and error behavior, unsolved. This is insufficient for an agent to confidently invoke the tool correctly.

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 8 parameters and 0% description coverage. The description does not explain any parameters, such as the relationship between a3/a3_pin/login_cpf/login_senha or optional cpf/cnpj. It only hints at paid consultations, not which parameter maps to credentials, vehicle, or renavam. With such low schema coverage, the description needs to compensate and does not.

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 a specific verb and resource: 'Imprimir CRLV-e, consulta em fonte oficial.' It identifies the tool as an official Brazilian vehicle document consultation and printing service, which is distinct from the generic sibling tools like authenticate, connect, or report_bug. The scope is further clarified by mentioning the official source and citizen-available information.

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 implies when to use the tool: when needing to query or print CRLV-e from official sources. It does not provide explicit alternatives or exclusions, and sibling tools are too generic, so there is little need for differentiation. However, there is no guidance about prerequisites, such as having prepaid credit or login credentials, beyond the fact that payment is required.

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