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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, so the safety profile is covered. The description adds pagination behavior (10 per page) and the fipeId outcome, but does not explain what the response returns beyond pagination or error behavior for invalid slugs.

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?

A single dense sentence front-loads the purpose, then immediately states the two usage modes with parameter names. Slightly long but every clause carries routing information. Minor deduction for the parenthetical example interrupting flow.

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 read-only search tool with full schema coverage and no output schema, the description covers purpose, the two invocation modes, pagination, and the fipeId goal. It does not describe return fields or how pagination metadata appears, but that is a minor gap given no output schema exists.

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 100%, so the schema already documents every parameter including the enum, max lengths, and the marca+modelo dependency. The description reinforces the two modes and pagination size but adds no syntax or format detail beyond the schema. Baseline 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?

States a specific verb (Acha versões de veículo) and resource (catálogo Carpedia), and explains the outcome (chegar num fipeId), which differentiates it from siblings like carpedia_buscar_modelos or carpedia_buscar_marcas.

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?

Explicitly gives two usage modes with conditions: free search with `termo` (optionally narrowed by `marca`), OR exact `marca`+`modelo` to list versions of a specific model. This tells the agent exactly which parameter combination selects which behavior.

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