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

Annotations already declare the operation read-only, idempotent, and non-destructive, so the description does not need to restate that. It adds some context about the returned subject matter (shareholders and linked companies), but it does not disclose behavior such as authentication needs, rate limits, or the effect of the optional 'completo' flag.

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, front-loaded sentence with no filler. It conveys the core idea efficiently: QSA, corporate holdings, shareholders, and linked companies for a CNPJ.

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 read-only lookup, the description gives enough context to understand the tool's purpose, but it still leaves invocation details ambiguous, especially the meaning of 'completo'. Since there is no output schema, some information about what the tool returns would also help.

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. It only mentions that CNPJ is the target entity and says nothing about the 'completo' boolean parameter, its default value, or what changes when true.

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 communicates a specific resource (CNPJ) and a specific data scope (QSA, shareholders, and linked companies), so an agent can tell what this tool returns. It lacks an explicit verb and does not clearly differentiate it from the closely related sibling investigacao_vinculos_societarios, so it falls just short of a 5.

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?

Usage is only implied: this is for investigating corporate ownership/participations for a CNPJ. There is no explicit guidance about when to use this over sibling tools, no exclusions, and no mention of required conditions such as needing a valid CNPJ.

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