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

Beyond the annotations (readOnly, idempotent, non-destructive), the description discloses important behavioral traits: no credentials required, pay-per-query model, public data source, and client data controller responsibility. These add significant context beyond the structured annotations, with no contradiction.

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 paragraph with no redundancy. It efficiently covers purpose, access model, and data privacy. It is slightly dense but every sentence adds necessary context, so it earns a 4.

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 two-parameter tool with no output schema, the description covers operational context (hosting, credentials, payment, data sensitivity, LGPD). It does not mention response format or error handling, but these are less critical given the tool's simplicity and good annotations.

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 explains the CIB parameter ('a partir do CIB') but does not explain the 'completo' boolean parameter. With two parameters and zero schema coverage, the description should clarify both or at least hint at the optional one's meaning.

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 specific action ('Emite a Certidão Negativa de Débitos e Dívida Ativa da União') and the resource (rural property, identified by CIB). This is a specific verb+resource combination that clearly distinguishes it from the generic 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 the tool is appropriate: it queries public-access information, requires prepaid credit, and involves LGPD responsibilities. However, there are no explicit alternatives or when-not-to-use conditions, so it falls short of a 5.

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