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 context: no platform credentials are needed, costs are incurred per query, and the client is responsible for LGPD compliance. This goes beyond the structured annotations and helps the agent understand the operational and legal context.

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 and front-loads the core purpose. Some legal boilerplate about LGPD and data control is included, which adds length but is arguably necessary for compliance. It remains reasonably concise and readable.

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 tool has a single parameter and no output schema, so the description carries the burden of explaining behavior. It covers purpose, cost, and data responsibility, but it does not describe the return value, error handling, or the expected format of the 'nfce' parameter. For a simple query tool, this is a noticeable gap.

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 one required parameter 'nfce' with no description, and schema description coverage is 0%. The tool description does not explain what the 'nfce' parameter should contain (e.g., the NFC-e access key format). Since the description fails to compensate for the missing schema details, parameter semantics are unclear.

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 performs a consulta (query) of NFC-e from SEFAZ PB using an official source. The verb 'consulta' and resource 'NFC-e' are specific, and it is clearly distinct from sibling tools like authenticate or marketplace.

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 usage context: it is hosted by the platform, requires no platform credentials, and is paid per query with prepaid credit. It also clarifies that the data is the same available to citizens and not confidential, implying when it is appropriate to use. However, it does not explicitly name alternative tools or state when not to use it.

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