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 this by stating 'sem credenciais da plataforma' (no platform credentials needed), 'pague por consulta com crédito pré-pago' (paid per query), and the LGPD data-controller responsibility. These details inform the agent about authentication, cost, and legal implications, going well beyond the annotation cues.

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 mixes essential query information with legal and financial disclaimers. It is reasonably concise at about 60 words, but it could be better structured to front-load the functional purpose before discussing payment and compliance details.

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?

For a tool with one parameter, no output schema, and read-only annotations, the description provides substantial context: the authoritative nature of the source, the lack of credential requirements, the pay-per-query model, and LGPD compliance responsibility. It covers the main aspects an agent needs to know, though it could mention response characteristics or error conditions.

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?

With 0% schema description coverage for the only parameter 'nfce', the description needed to compensate, but it does not explicitly explain what the parameter is or its expected format. The letter 'nfce' is mentioned in the tool name and description, and the parameter name is identical to the acronym, but there is no clarification about whether it's a key, number, or URL, nor any example or format hint.

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 this is a query ('consulta') for NFC-e data from SEFAZ SP, and it is described as accessing official Brazilian sources. While it lacks the explicit sibling-distinguishing language seen in higher-scoring examples, the tool name and description together leave little doubt about its function.

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?

There is no guidance on when to use this tool versus alternatives, nor any exclusion criteria or alternative tool references. The description focuses on commercial and legal caveats (pay-per-query, LGPD) rather than providing usage context or prerequisites.

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