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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds useful behavioral context beyond annotations: the exact endpoint and a 1-hour cache, which informs an agent about data freshness and repeated-call expectations.

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 compact and front-loaded: the purpose appears first, followed by the endpoint, applicability, and cache behavior. Every sentence carries useful information, and there is no redundancy with the schema or annotations.

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 low-complexity read-only query tool with three optional, fully described parameters and an output schema present, the description provides sufficient context: what is queried, when it applies, where to call, and how caching behaves. No critical operational detail 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 the input schema already documents all three parameters (cnpj, nome, pagina) with meaningful descriptions. The tool description itself adds no additional parameter-level semantics, which is acceptable given the schema's completeness.

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 a specific verb ('Consulta') and a specific resource ('CEPIM — Entidades Privadas Sem Fins Lucrativos Impedidas'), making the tool's function immediately clear. It also adds an applicability context (convênios and termos de fomento with OSCs), which distinguishes it from sibling sanction-registry tools like CEIS, CNEP, and CEAF even without naming them.

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 explicitly states when the tool applies: contratações via convênios and termos de fomento with OSCs. It does not, however, contrast this with alternative sanction tools or provide explicit exclusions, so it stops short of full when-not guidance.

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