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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds valuable context: it is hosted by the platform, requires no platform credentials, is paid per query with prepaid credits, and clarifies data privacy (LGPD) and that data is not confidential. This goes beyond annotations and helps the agent understand operational constraints.

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 a single paragraph with three sentences, each adding distinct information: purpose, operational details, and legal context. It is concise and front-loaded with the core purpose. No wasted words, though it could be slightly more structured with bullet points, but it is acceptable.

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?

Given the tool's simplicity (one parameter, no output schema), the description covers the essential aspects: what it does, how it is accessed (paid, prepaid), and legal considerations. It does not describe the return format, but since there is no output schema, the description could have mentioned what the response contains. However, for a simple query tool with good annotations, this is reasonably complete.

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 one required parameter 'nfce' with no description, and schema description coverage is 0%. The description does not explain what 'nfce' should contain (e.g., the access key format, length, or example). However, with only one parameter and a clear name, the meaning is somewhat inferable, but the description should have provided format details to compensate for the lack of schema 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 clearly states the tool queries the official SEFAZ BA source for complete NFC-e data, distinguishing it from a generic query by specifying the state (BA) and type (Completa). It does not explicitly contrast with sibling tools, but the siblings are unrelated (auth, connect, etc.), so the purpose is clear enough.

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 implies usage for consulting official Brazilian tax documents, but it does not provide explicit when-to-use or when-not-to-use guidance, nor does it mention alternatives. It does clarify that it is a paid per-query service with prepaid credits, which gives some context, but no exclusions or alternative tool references.

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