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

Beyond the annotations (readOnly, idempotent, non-destructive), the description adds practical behavioral details: the tool is hosted by the platform, requires no platform credentials, is paid per query with prepaid credit, and returns only non-confidential official data. It also addresses LGPD data-controller responsibilities, providing a fuller operational picture than the annotations alone.

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 front-loaded with the core purpose and remains relatively short. The legal LGPD sentence adds compliance context but is somewhat auxiliary; overall, every sentence earns its place without excessive verbosity.

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?

The description covers purpose, authentication/cost model, data source, and legal responsibility, but it lacks any indication of the return format or the specific structure of the `nfce` parameter. Since there is no output schema, the absence of output details leaves a notable gap for an agent invoking this tool.

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 has zero schema coverage for the only parameter `nfce`. While the tool name and description imply the parameter is a NFC-e document reference, its required format, source, or how to obtain/validate it is not explained. The description fails to compensate for the missing schema documentation, leaving an agent guessing how to construct a valid call.

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 identifies the tool as a query ('consulta') for NFC-e data from SEFAZ DF, an official Brazilian source. The resource and action are specific, and the description distinguishes it from the generic sibling tools (authenticate, connect, etc.) by indicating its domain-specific purpose.

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 context: it should be used to consult official NFC-e data available to citizens, and it clarifies payment via prepaid credits and lack of platform credentials. It does not explicitly mention alternatives or when-not-to-use, but the implied usage is strong and the sibling tools are unrelated, so exclusions are unnecessary.

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