buscar_endereco_por_cep

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

No annotations are provided, so the description carries the burden. It discloses the return fields and the flexible CEP format, which is helpful. However, it does not mention potential errors (e.g., invalid CEP), dependencies (e.g., external service), or explicitly confirm that this is a read-only operation. For such a simple query tool, some of this is implied, but the description could be more transparent about failure behavior.

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 sentences long, with the first sentence stating the purpose and return fields, and the second specifying the input format. There is no redundant or extraneous information. It is appropriately front-loaded and concise.

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 tool's low complexity (single parameter, no output schema, no annotations), the description is largely complete. It covers the purpose, input format, and the fields returned, partially compensating for the lack of an output schema. It does not address error cases, but this is a minor gap for such a straightforward lookup tool.

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?

Schema description coverage is 100%, so the schema already fully documents the 'cep' parameter, including format requirements and examples. The tool description repeats this information without adding new meaning. Therefore, the parameter semantics add no value beyond the schema, warranting the baseline score of 3.

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 function: consulting complete Brazilian address information from a CEP. The verb 'consulta' and resource 'endereço brasileiro a partir do CEP' are specific, and the listed return fields (logradouro, bairro, cidade, etc.) further clarify the scope. It also distinguishes from the sibling tool (buscar_cep_por_endereco) by emphasizing the direction: from CEP to address.

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 that this tool should be used when you have a CEP and need the full address. It clearly states the input format (with/without hyphen), but it does not explicitly mention alternatives or when not to use it. However, the sibling tool's name provides clear differentiation, and the context is unambiguous.

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