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 meaningful behavioral context beyond those: it is a paid consultation (prepaid credit), does not require platform credentials, accesses non-confidential official data, and places LGPD responsibility on the client. This goes beyond the annotations and provides useful operational details.

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 (4 sentences), front-loaded with the main purpose, and each sentence adds distinct information: purpose, payment model, data source, and legal compliance. No redundant content, though the flow could be slightly more structured.

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?

With 4 required parameters, no parameter descriptions, no output schema, and no explanation of expected inputs or return values, the description is not complete enough to guide an agent in correct invocation. It covers the 'why' and legal aspects but leaves out the 'how' (parameter meanings) and 'what to expect' (output format).

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 input schema has 4 required parameters with no descriptions (0% schema coverage), and the description does not explain what 'cdc', 'finalidade', 'cpf_solicitante', or 'telefone_solicitante' mean. The only indirect hint is the LGPD mention of 'finalidade legítima', which may relate to the 'finalidade' parameter, but this is insufficient for correctly populating the required fields.

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: 'Certidão Tributária de IPTU, consulta em fonte oficial' (IPTU Tax Certificate consultation from an official source). It uses a specific verb (consulta) and names the resource, distinguishing it from the generic sibling tools (authenticate, connect, 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 how the tool is used: hosted by the platform, no platform credentials needed, prepaid credit payment, and it accesses official Brazilian sources. However, it does not explicitly state when to use this tool over alternatives or mention any exclusions. The siblings are unrelated, so the lack of alternatives is less critical, but the usage context is implied rather than explicit.

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