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

The description adds behavioral details beyond the annotations: it indicates that no credentials are needed, that payment is required, and that the data is not confidential. These are useful and do not contradict the readOnly/idempotent hints provided in the annotations.

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 relatively concise but contains slight redundancy (e.g., repeating 'fonte oficial' and 'oficiais brasileiros'). Still, it is short and directly relevant, with no unnecessary fluff.

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?

It covers the core purpose, access, and cost, but lacks information about the output (e.g., what the returned certificate contains) and does not elaborate on edge cases or usage context. Given the simplicity of the tool, this is adequate but not comprehensive.

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?

The description does not explain any of the three parameters (cpf, cnpj, nome). Since the schema lacks descriptions and the tool description provides no hints about what these parameters mean, the description adds no value to parameter understanding.

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 tool performs a consultation (consulta) of the Electronic Certificate of Labor Actions (CEAT) from an official source, which is a specific verb and resource. It distinguishes itself from generic sibling tools like 'authenticate' or 'show_version' by specifying the domain.

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 mentions that the query is from an official source, is hosted on the platform, requires no platform credentials, and is paid per query with prepaid credits. While this gives context on cost and access, it does not explicitly state when to use this tool versus alternatives or when not to use it.

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