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

Annotations already establish read-only and non-destructive behavior. The description adds valuable context: no credentials required, pay-per-query model, data is public and not confidential, and LGPD compliance responsibilities. This goes beyond the structured annotations without contradicting them.

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 concise, with four sentences each serving a purpose: stating the function, explaining hosting/payment, clarifying data nature, and noting LGPD responsibility. It is directly front-loaded with the purpose, making it easy to parse quickly.

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 query tool with two parameters and no output schema, the description covers the primary function, input, cost, and data sensitivity. However, it omits an explanation of the 'completo' boolean parameter and possible response details, which would enhance completeness. Overall, it is largely sufficient.

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 0%, so the description must compensate. It clearly indicates the main input is CNPJ ('a partir do CNPJ'), but it does not explain the optional 'completo' parameter or provide format details. This partial explanation adds some value but leaves ambiguity for the optional parameter.

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's function: 'Verifica se uma entidade privada sem fins lucitativos consta no CEPIM' (checks if a non-profit entity appears in CEPIM). It uses a specific verb ('verifica') and resource ('CEPIM'), and distinguishes from sibling tools which are platform-level actions (authenticate, connect, marketplace, etc.).

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 context on when to use the tool: it is hosted by the platform, requires no credentials, and is paid per query with prepaid credit. It also clarifies the data is public access. However, it does not explicitly state when not to use it or mention alternative tools, which are not needed given the unrelated siblings.

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