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

Annotations already declare readOnlyHint=true, openWorldHint=false, idempotentHint=true, and destructiveHint=false. The description adds valuable behavioral context: queries official Brazilian government sources, returns the same data available to citizens, is not confidential data, involves prepaid per-query billing, and imposes LGPD responsibilities on the client as data controller. This exceeds what annotations provide without contradiction.

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?

Four sentences cover purpose, hosting/billing, data source, and legal obligations. The information is logically ordered and front-loaded with the primary purpose. Minor deduction for the dense acronyms (ECRVSP, RENAINF) and boilerplate LGPD language that could be replaced with parameter-related guidance.

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 high complexity (8 params, 5 required, no output schema, no parameter descriptions), yet the description provides no information about return values, date formats, auth parameter roles, or how 'exigibilidade' affects the request. The legal and billing disclaimers, while relevant, do not help an agent construct a correct call or interpret the response, leaving critical gaps for a typical integration workflow.

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% across 8 parameters, and the description fails to explain any of them. Only 'placa' is inferable from the tool name, while a3, a3_pin, login_cpf, login_senha, data_inicio, data_fim, and exigibilidade remain entirely undocumented. The phrase 'sem credenciais da plataforma' gestures at authentication but is too vague to compensate for the lack of parameter 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?

Describes the tool as querying Brazilian traffic fines by license plate ('Por Placa, consulta em fonte oficial'), making the core verb and resource clear. Distinguishes from siblings in that no sibling is a similar query tool, though the purpose is somewhat buried under promotional and legal text. Loses a point for unnecessary jargon and extraneous detail.

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?

No explicit guidance on when to use this tool versus alternatives, no prerequisites beyond paying with prepaid credit, and no exclusion criteria. The mention that it queries the same data available to citizens implies access limits but does not help an agent decide between this and another tool. Score 2 due to the complete absence of comparative or conditional usage guidance.

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