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

Annotations already declare readOnly, idempotent, non-destructive behavior. The description adds useful behavioral context: no platform credentials are required, payment is per-query via prepaid credit, and the data is non-confidential/citizen-accessible. It also notes LGPD-related responsibility, which is meaningful for an agent deciding whether to call the tool.

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 front-loaded with the core purpose, followed by concise operational and legal context. Every sentence contributes information relevant to an agent's decision to invoke the tool: what it does, how it is billed, what data scope applies, and legal responsibility.

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 simple one-parameter lookup with safety covered by annotations, the description is largely complete: it states data source, credential requirements, billing model, and data sensitivity. It could spell out the expected license-plate format or describe the return payload, but the absence of an output schema lowers the burden.

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, 'placa', with no description (0% schema description coverage). The tool description never mentions the parameter or expected format, so it does not compensate for the missing schema guidance. The parameter name and tool name make the intent somewhat inferable, but the description adds no direct semantic value.

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 opens with 'DETRAN MG: IPVA, consulta em fonte oficial', naming a specific resource (DETRAN-MG IPVA) and action (consulta). This clearly identifies the tool's function and differentiates it from the unrelated sibling tools like authenticate and 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 clear operational context: it is a paid, prepaid-credit lookup from official Brazilian sources, with no platform credentials required. It does not explicitly name alternatives or exclusion conditions, but the intended use case is strongly implied and context is clear.

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