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

The description goes beyond the provided annotations by explaining the `rotulo` field that distinguishes full cost from IPVA-only, and clarifies that `estimativa` is always true. This adds behavioral detail and is consistent with the readOnly and idempotent hints.

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 moderately concise, containing three sentences with necessary clarifications. It is slightly verbose due to repeating the note about `rotulo` and `estimativa`, but remains focused and readable.

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 absence of an output schema, the description adequately explains the output semantics (label values and estimate flag) and clarifies that depreciation is a statistical projection, not official FIPE data. This provides sufficient context for understanding the tool's behavior, though it lacks explicit use-case examples.

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 already provides complete descriptions for all three parameters (uf, ano, fipeId). The tool description does not add additional parameter-level nuance beyond what the schema states, so a baseline score of 3 is appropriate.

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 that the tool estimates annual usage cost with specific components (depreciação, IPVA, combustível/energia) and differentiates from official FIPE tables. It does not explicitly name a sibling tool but the purpose is unambiguous.

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 is provided on when to use this tool versus siblings like carpedia_preco_fipe or carpedia_consumo. The description explains what it does but does not state selection criteria.

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