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

With no annotations, the description carries the full burden and does well: it discloses the credit cost (1 crédito per emitted certificate), the 24h reuse rule, and that failures are not charged. The cnpj filtering behavior is also described. It stops short of describing the response shape or what fields are returned per entry, which keeps it from a 5.

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 dense but every clause earns its place: catalog contents, cnpj scoping, id-family semantics with an example, and billing rules. Content is appropriately front-loaded with what the catalog contains, though the id-family explanation is somewhat compact for an unfamiliar reader.

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 no-annotation, no-output-schema, single-optional-param tool, the description covers the catalog contents, filtering, id semantics for downstream use, and cost behavior. The main gap is the absence of an explicit action statement and any hint of return structure, but overall an agent has enough to call it correctly.

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 coverage is 100% for the single cnpj parameter, so the schema already documents it. The description restates the filter ('só as certidões que valem para esta empresa') and adds only the 'pela sede na Receita' detail, so it adds marginal value over the structured field. Baseline 3 applies.

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 establishes the resource: a catalog of certificates (certidões) with their órgão, validity, fee, and automatic-emission status. The verb 'list' is only implicit ('Certidões que buscamos'), but the scope is concrete enough that an agent knows it returns the certificate catalog rather than executing a diligence. It also names create_diligence, helping distinguish its role.

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?

It explicitly links its output to create_diligence, explaining that 'trt'/'trf' family ids can be passed as id while regional ids (trt15, trf1) target a specific court, with a worked example (TRT-15 for a Campinas branch). That is real when-to-use guidance, though it never states flatly 'call this to discover available certificates before creating a diligence' or any exclusion.

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