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

Annotations already declare readOnlyHint and idempotentHint, and the description adds valuable context such as no platform credentials required, prepaid credit payment, non-confidential data source, and LGPD responsibility for the client. This goes beyond annotations and helps the agent understand costs and legal implications.

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 four sentences, front-loaded with purpose, then adds payment, data source, and legal details. It is slightly verbose but each sentence provides distinct and useful information, making it efficient overall.

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 tool with 2 optional params and no output schema, the description covers purpose, payment, and legal aspects but omits critical details about the parameters (cpf/cnpj), their optionality, and what the tool actually returns. This leaves gaps for confident invocation.

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 schema has two parameters (cpf and cnpj) with no descriptions, and the description does not mention them at all. Since schema coverage is 0%, the description must compensate by explaining the parameters, but it fails to do so, leaving the agent to assume their purpose and relationship.

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 consults a Certidão Negativa de Débitos from Prefeitura PR Curitiba using the verb 'consultar' and specifies the resource. It distinguishes itself from generic sibling tools like authenticate or show_version by naming a specific city and certificate type.

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 gives clear context: it is hosted, requires prepaid credits, and does not need platform credentials. However, it does not explicitly state when to use this tool over alternatives or provide exclusions, though the specific city and certificate type imply its unique use case.

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