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

Annotations already declare readOnly, idempotent, openWorld and non-destructive, so the safety profile is covered. The description adds value beyond that: it says the call is free, that results are canonicalized names, that a model hit carries a stable per-year vehicle id, and that the id should be passed as `vehicle` to the image and 3D tools — useful chaining context. It stops short of stating result caps or truncation behavior beyond the schema's limit.

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?

Three sentences, front-loaded with the leading qualifier "Free" and the scope, and every sentence carries distinct information (capability, return shape, routing). The parenthetical about ids is dense and slightly hard to parse, which keeps it off a 5.

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 3-parameter read tool with an output schema and full annotation coverage, this description supplies everything an agent needs: scope, matching rules, return shape, id handoff to sibling tools, and routing versus resolve_vehicle.

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 coverage is 100%, so baseline is 3; the description adds meaning by explaining the query semantics ("fewer words find more: every word must be in the name of one catalog vehicle") and typo tolerance, and by linking the year dimension to per-year id granularity. It does not elaborate on `limit` or on how `year` interacts with ranking, so it is not exhaustive.

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 and resource (browse the vehicle catalog) plus concrete scope (1,608 makes, 42,321 models, 1990-2027) and matching behavior (make/model with typo tolerance). It also names what it is not — resolve_vehicle — so an agent can distinguish the two without opening either schema.

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 lists the intended cases (list a make's models, check which years exist, let a human choose between similar models) and the exclusion with a named alternative: when the car is already known, resolve_vehicle is the one call. Both when-to-use and when-not-to-use are covered.

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