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

Annotations cover the safety profile (readOnly, idempotent, non-destructive, openWorld), so the bar is lower, yet the description adds substantial behavior: parallel fan-out to four sources, partial-return semantics (failed sections arrive as null and are listed in secoes_com_falha, per-source status in fontes, completo only when nothing failed), and coverage caveats (federal sphere only, absence ≠ non-existence, no completeness guarantee).

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?

Purpose and when-to-use are front-loaded, and the return-shape and limitation sentences each carry distinct information. It is long, but this is a complex aggregator and nearly every clause earns its place; only the limite_contratos recap is mildly redundant.

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 multi-source aggregator with an output schema and full annotations, the description still supplies the failure semantics, coverage limits, and scope disclaimers an agent needs to interpret results responsibly. Nothing material is missing.

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 100%, so both parameters are already documented in the schema; the description's restatement of limite_contratos (1–100, default 10) and the with/without-mask CNPJ note duplicates rather than extends the schema. Baseline 3 is appropriate where the schema does the heavy lifting.

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?

States a specific verb+resource (full Brazilian-company check report by CNPJ) and enumerates exactly what it aggregates: cadastro/Receita Federal, sanções/CEIS-CNEP-CEPIM, contratos federais, and CVM registry. It also distinguishes itself from the per-source siblings by framing itself as the aggregate call and the individual tools as the faster alternative.

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 'Quando usar' clause names concrete scenarios (checagem inicial, KYC, due diligence) and provides an explicit exclusion plus alternative: when only one part matters, the individual tool is faster. The section names (cadastro, sanções, contratos, cvm) map directly onto the sibling tools, so the routing is inferable without opening any schema.

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