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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false. The description adds valuable context: no credentials needed, prepaid per-query cost, access to public official data, and LGPD compliance. It also clarifies the client's responsibility as data controller. Nothing contradicts the annotations, and the added legal/billing context goes beyond structured fields.

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 focused four-sentence paragraph that front-loads the core purpose, then adds billing and legal context. It is not overly verbose, though some content (LGPD clause) could be considered tangential for an AI agent. Overall, it is efficiently structured and earns its place.

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 read-only tool with no output schema, the description covers the purpose, authentication, cost, data source (public official bases), and legal obligations. It does not describe return value format or pagination, but given the tool's simplicity and presence of readOnlyHint, the description is sufficiently complete for selection and invocation. Sibling tools offer no alternative, so no comparison is needed.

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 0%, so the description must compensate for explaining parameters. It does not mention either 'CNPJ' or 'completo' explicitly. The CNPJ parameter is self-explanatory from the tool name and description, but the 'completo' boolean is ambiguous—whether it controls the depth of data returned is not stated. The description says 'além dos dados básicos' which hints at a 'complete' mode, but this is not explicit. Thus, the description adds little parameter-level meaning.

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 states the tool returns "Dados cadastrais ampliados de uma empresa a partir do CNPJ, além dos dados básicos," clearly specifying the resource (CNPJ) and the scope (expanded corporate data). It distinguishes itself from the unrelated siblings (authenticate, connect, etc.) and the verb is implicit in the tool name 'consultar'.

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 clear context on how to use the tool: it is hosted by the platform, requires no credentials, and charges per query with prepaid credit. It also notes the data is public and LGPD applies, but it does not explicitly discuss alternative tools or when not to use it. Given the sibling tools are unrelated, this is acceptable and achieves a clear context without explicit exclusions.

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