consultar_cep

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

With no annotations provided, the description carries the full burden of explaining behavior. It discloses what the tool returns (address components and origin service) and accepted input formats, but does not mention error handling, invalid CEP behavior, or any potential service limitations. This is acceptable but not exhaustive.

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 concise, consisting of two short sentences that avoid unnecessary detail or repetition. It front-loads the purpose and then adds essential output and input format details.

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?

Although the output schema is indicated as present, the description already summarizes the return fields, which is sufficient for a simple lookup tool. It does not mention failure cases or external dependencies, but for the scope of this advisory tool, the description is complete enough.

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 parameter 'cep' is fully described in both the schema and the description, including format examples and the option to use a hyphen. Since schema coverage is 100%, the baseline is 3, and the description adds value by clarifying the accepted format, justifying a 4.

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 tool's purpose: to query the complete address from a Brazilian CEP. It specifies the resource (CEP) and the output fields (logradouro, bairro, cidade, estado, serviço de origem), distinguishing it from sibling tools focused on CNPJ, CPF, taxes, or NF-e.

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 an address lookup from a CEP is needed) and provides input format guidance (with or without hyphen, examples given). It does not explicitly name alternatives or state when not to use it, but no close alternatives exist among the listed siblings.

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