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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, establishing it as a safe, read-only operation. The description adds that it returns specific address components (logradouro, bairro, cidade, UF), which is useful context. It does not discuss error handling, rate limits, or explicit auth requirements, but given the annotations cover the safety profile, a midpoint score is appropriate.

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 two concise sentences, front-loaded with the primary action ('Consulta um CEP e devolve...') and then a practical use case. No filler or redundancy; every word earns its place, making it efficient for an agent to parse quickly.

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?

For a simple single-parameter, read-only lookup tool with no output schema, the description adequately covers purpose, output fields, and a use case. It does not mention error scenarios (e.g., invalid CEP) or network behavior, but these are not critical for the agent to decide whether to call the tool. The description is complete enough for correct invocation.

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 provides only a string parameter named 'cep' with 0% description coverage. The description says 'Consulta um CEP' but does not explain the expected format (e.g., digits only, with or without hyphen, country code). For a tool in a Brazilian context, the parameter name is self-explanatory, but the description fails to elaborate on constraints or syntax, leaving the agent to infer from the name alone. With no schema description, the description should compensate more explicitly.

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 function: 'Consulta um CEP e devolve logradouro, bairro, cidade e UF.' It specifies the verb (consulta), the resource (CEP), and the concrete output fields. This distinguishes it from all sibling tools, which are about quotes, dashboards, or authentication, so intent is 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 provides a concrete use case: 'Útil para preencher endereço de risco/pernoite ao montar uma cotação.' This tells an agent when to invoke it (during quote assembly for risk/address filling). It does not mention when not to use it or list alternatives, but for a simple lookup tool, this level of guidance is sufficient and clear.

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