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

The description adds significant behavioral context beyond the annotations: it discloses that no platform credentials are needed, there is a cost per query ('pague por consulta com crédito pré-pago'), and it clarifies data sensitivity and LGPD compliance ('não é dado sigiloso', 'O cliente é o controlador dos dados'). This enriches the agent's understanding of side effects and legal implications, going beyond the simple `readOnlyHint` and `idempotentHint` annotations. It does not contradict any annotation.

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 block of 4-5 sentences that front-loads the core purpose but then dives into billing and legal disclaimers. While all information is relevant, the LGPD notice could be streamlined for an LLM context. It is not overly long but could be more concise and better structured (e.g., using bullet points) to improve scannability. It earns a middle score because it's not excessively verbose but not maximally efficient.

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 2-parameter lookup tool with no output schema, the description covers purpose, billing, and legal context. However, it omits any mention of output format (e.g., what the returned code looks like) and leaves parameter details to the imagination. The absence of parameter descriptions is a notable incompleteness given the entire tool hinges on correct parameter values. It's a borderline acceptable description for a trivial tool but has clear gaps.

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?

With 0% schema description coverage, the description was expected to compensate by explaining the parameters (`uf` and `municipio`). It does not. The description never mentions the parameters, their expected formats (e.g., UF as a two-letter state code, `municipio` as a name string), or examples. This is a critical gap; the agent is left to infer parameter semantics solely from the parameter names and tool name.

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 'Código de Município, consulta em fonte oficial' (Municipality Code, query from official source), which is a specific verb+resource+scope. It distinguishes this tool from generic sibling tools like 'authenticate' or 'marketplace', leaving no ambiguity that this is for querying IBGE municipality codes. The tool name also reinforces the purpose.

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 implicit usage context by mentioning 'consulta' (query) and the official source, making it clear this is the tool for IBGE municipality code lookups. However, it does not explicitly state when to use this tool over alternatives or when not to use it. The billing and authentication details ('sem credenciais da plataforma, pague por consulta com crédito pré-pago') hint at operational constraints but don't provide usage exclusions or alternatives.

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