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

The annotations already declare readOnly, idempotent, non-destructive. The description adds valuable context beyond that: it mentions the service is hosted on the platform, requires payment with pre-created credits, does not require platform credentials, and clarifies that the data is not confidential and falls under LGPD responsibility. These details help the agent anticipate side-effects (cost) and obligations, which the annotations alone do not provide.

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 long sentence that packs the purpose, payment, and legal obligations into one block. It is somewhat dense but avoids unnecessary fluff. The information is front-loaded with the core purpose, but the LGPD sentence at the end might be considered extra. It is not overlong, but lacks structure (e.g., bullet points or separate paragraphs) which could improve readability.

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 there is no output schema and only 3 parameters, the description is incomplete. It does not explain the expected invocation pattern (which parameters to provide or in what combos), the meaning of 'preferencia_emissao', or what output/response to expect (PDF, certificate code, etc.). It also does not state any error conditions or limitations. The tool is essentially underspecified for successful use.

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 lists three parameters (cpf, cnpj, preferencia_emissao) with zero schema descriptions and 0% coverage. The tool description does not mention any of these parameters, their formats, semantics, or relationships (e.g., whether CPF and CNPJ are alternatives or required together, or what 'preferencia_emissao' refers to). This forces the agent to guess, which is a severe gap.

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 identifies the tool's purpose with a specific verb ('consultar' i.e., query) and resource ('Certidão Negativa de Débitos' from Prefeitura de Rondonópolis). It is distinct from the sibling tools which are all platform-level operations (authenticate, connect, etc.), so the purpose is unambiguous and easily differentiated.

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 usage for querying official public data on negative debt certificates, but does not explicitly state when to use it versus any alternatives (though none exist among siblings). The mention of 'the same source available to citizens' gives context that this is a public data lookup, but there is no clear exclusion or comparison against other querying tools.

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