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 behavioral context beyond that: it discloses payment per query, no credentials required, public-access data, and LGPD responsibilities for the client. This exceeds minimal annotation coverage, though it omits potential edge-case behavior or rate limits.

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 front-loaded with the core purpose in the first sentence, followed by payment, access, and legal context. Most sentences serve a distinct purpose, though the explanation of public access is slightly redundant ('ACESSO PÚBLICO' + 'não é dado privado nem sigiloso'). Overall, it remains efficient and readable.

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?

The tool has three parameters and no output schema, so the description carries significant responsibility. It adequately covers the tool's function, payment model, and data sensitivity, but it does not describe the return format, behavior when a record is not found, or the 'completo' parameter. This leaves notable gaps for an agent deciding whether to invoke it and interpreting results.

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 description clarifies that CPF and CNPJ are the identifiers used for the query, which gives meaning to those two parameters. However, the 'completo' parameter is entirely unexplained, and there is no mention of the expected format or the odd requirement that both CPF and CNPJ are marked as required. Since schema coverage is 0%, the description only partially compensates.

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 consults CVM registration records for individuals or legal entities using CPF or CNPJ. The verb 'Consulta' plus the specific resource (CVM cadastro) and input identifiers leave no ambiguity about the tool's purpose, and it is distinct from the sibling tools.

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 about when to use the tool (consulting public CVM data), including practical details like being hosted, no credentials, and prepaid credit. However, it does not explicitly exclude alternative tools or state 'when not to use,' so it stops short of full usage guidance.

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