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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It mentions 'Grátis' (free) and that it returns distances and addresses, but it does not state whether the operation is read-only, whether authentication is needed, what happens on invalid input, or any rate limits. This is a significant gap for a tool with no annotation coverage.

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 a single, compact sentence that front-loads the key purpose (return CEPs within a radius), mentions the input options, and notes the output fields and cost. Every word earns its place, with no redundancy or fluff.

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 simplicity (4 optional parameters, no output schema), the description is fairly complete: it states what is returned (CEPs with distance and addresses) and the free cost. However, it does not clarify the mutual exclusivity of 'cep' vs 'lat'/'lon' or the default radius value, though these are present in the schema. For a simple tool, this is adequate.

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 input schema has 100% description coverage, so the baseline is 3. The description adds minimal extra meaning beyond the schema: it explains the concept of a radius ('N metros') and the two possible center types (CEP or lat/lon), but these are already implied by the schema fields. No additional semantics about parameter interaction (e.g., precedence when both 'cep' and 'lat'/'lon' are provided) are given.

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 returns CEPs within a radius from a point (CEP or lat/lon), including distance and addresses. It uses a specific verb ('returns') and resource ('CEPs'), and mentions the optional input types. However, it does not explicitly differentiate from sibling tools like 'cep' or 'proximo', which likely have related purposes.

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 you need CEPs within a radius from a point) but provides no explicit guidance on when not to use it or which sibling tools to prefer as alternatives. The sibling list includes 'cep', 'proximo', and 'vizinhanca', which could overlap, but no comparison is offered.

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