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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false. The description adds valuable behavioral context beyond annotations: prepaid credit is consumed, no platform credentials are required, the data is non-confidential and publicly available to citizens, and LGPD data-control responsibilities apply. No contradiction is present.

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 reasonably concise and front-loaded with the core purpose. The later sentences add useful operational and legal context, though there is some minor redundancy between 'consulta em fonte oficial' and 'fontes e órgãos oficiais brasileiros'.

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?

Despite good high-level context about payment, credential model, and data sensitivity, the tool has six undocumented parameters and no output schema. The description does not explain authentication setup, how to obtain or format the PKCS12 certificate, what the receipt download returns, or error behavior, leaving significant gaps for correct 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?

Schema description coverage is 0% with six string parameters, and the description does not explain the meaning of email, senha, tipo_login, pkcs12_cert, pkcs12_pass, or numero_pedido. The phrase 'Download de Recibo' hints that numero_pedido matters, but this is insufficient to compensate for the complete lack of parameter documentation.

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 opens with a clear verb and resource: 'Download de Recibo, consulta em fonte oficial', making the tool's purpose explicit. The phrase 'Registradores (ARISP) Certidão' distinguishes it from generic sibling tools like authenticate, marketplace, and show_version.

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 usage context: the tool is hosted by the platform, requires no platform credentials, is paid per query with prepaid credit, and queries official Brazilian sources. It does not explicitly state when not to use the tool or name alternatives, but the context is strong enough for selection.

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