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 known. The description adds important context: it's hosted by the platform, requires prepaid credit, and the client is data controller (LGPD). This goes beyond annotations and helps the agent understand external 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, dense paragraph that is front-loaded with the tool's purpose. It includes several relevant caveats (no credentials, prepaid credit, LGPD). It is reasonably concise given the amount of regulatory context it conveys, though it 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?

The tool has 4 parameters, no output schema, and low schema description coverage. The description lacks detail on how to construct the query (e.g., whether cpf or cnpj is needed, what the returned data looks like, potential errors). Given the moderate complexity, the description is not fully complete for an agent to use it without additional exploration.

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%, so the description must compensate for parameter meaning. The description does not explain any parameter roles beyond the schema's property names. It mentions 'numero_nota' and 'codigo_verificacao' implicitly in the description but does not explain how those are used, nor the optional cpf/cnpj. Since coverage is 0% and the description adds nothing about parameters, the score is low.

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 NFS-e (electronic service invoice) data from the official Recife, PE source. It specifies the resource (NFS-e) and the action (consulta). It distinguishes from siblings (none are similar since siblings are generic platform tools like authenticate or report_bug).

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 explains the context: it uses official sources, is available to citizens, requires prepaid credits, and does not require platform credentials. It does not explicitly say when to use this tool vs alternatives, but given the siblings are unrelated, the context is clear. It also implies compliance responsibilities.

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