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

The description provides additional behavioral details beyond the annotations: it is a paid service (prepaid credits), requires no credentials, uses official Brazilian sources, and states that the data is not confidential and falls under LGPD with the client as controller. This goes beyond the simple read-only and idempotent hints.

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 repetitive, saying essentially the same thing multiple times ('consulta em fonte oficial', 'consulta informação de fontes e órgãos oficiais brasileiros', 'não é dado sigiloso'). It lacks a clear, structured presentation and could be condensed into a single concise sentence without losing meaning.

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?

The description does not explain what the tool returns, how to handle errors, or any specific usage details beyond the fact that it is a paid query. There is no output schema and the input parameters are not elaborated. The tool seems simple, but the description leaves many operational aspects unaddressed, making it incomplete for a user unfamiliar with GRT or the service.

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 lists cpf, cnpj, and renavam, but the description does not explain their roles or which are required. Although renavam is marked required in the schema, the description gives no guidance on how cpf/cnpj relate or are used. The field names are self-explanatory, but the lack of any additional meaning or usage context is a clear gap.

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 that the tool consults GRT (Guia de Regularização de Taxas) from DETRAN RJ, which is a distinct purpose compared to sibling tools like authenticate or marketplace. The verb 'consultar' and the resource 'GRT' are specific and unambiguous.

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 usage when one needs GRT information, but it does not explicitly state when to use this tool versus alternatives, nor does it provide usage scenarios or prerequisites. It mentions payment with prepaid credits, which is a relevant usage condition, but not comprehensive guidance.

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