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 covered. The description adds the specific ad-level facts included (color, doors, seller, source, km, link), which is useful context. It does not describe error behavior, response shape, or edge cases, but for a read-only single-ID getter this is acceptable.

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, front-loaded sentence that lists the relevant output fields first and then gives the usage directive. Every part earns its place, with no filler or redundant restatement of the tool name.

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?

Given the tool has only one required parameter and no output schema, the description provides enough information for an agent to invoke it correctly: it identifies the target ('este carro') and the expected content of the result. It could mention how this relates to get_vehicle_by_id or get_technical_specs, but the core usage is clear.

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 carries the burden for explaining car_id, but it never mentions the parameter directly. The phrase 'este carro específico' only weakly implies that car_id identifies the listing. The parameter name is self-explanatory, but the description adds no explicit meaning beyond the schema.

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 identifies the resource: 'Fatos do próprio anúncio' and lists concrete data fields (cor, portas, opcionais, vendedor, fonte, km, link). It also states the use case: direct questions about a specific car. However, it lacks an explicit verb and does not name or differentiate against the closest sibling tools such as get_vehicle_by_id or get_technical_specs.

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 gives a clear invocation context: 'Use para perguntas diretas sobre este carro específico.' This tells an agent when to select this tool. It does not provide exclusions or mention when a sibling would be more appropriate, so it stops short of full guidance.

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