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

Annotations already declare readOnlyHint=true, so the safety profile is covered. The description adds real value beyond that: the dependency on exact slugs from resolve_vehicle and the mandatory VIN-confirmation caveat for safety-critical decisions, which annotations do not convey.

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 tight sentences with no filler; usage guidance and the prerequisite are front-loaded. Slightly under-informative on what is returned, but appropriately sized overall.

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?

With an output schema covering return values and annotations covering the read-only safety profile, the description only needs to carry usage and prerequisites, which it does. A mention of how it relates to get_known_issues/get_vehicle_summary would make it complete.

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%; each field already states it is a slug from resolve_vehicle with examples. The description's 'Requires exact slugs from resolve_vehicle' repeats what the schema already documents, so it adds no format or semantic detail beyond it. Baseline 3 applies.

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?

Identifies the resource clearly as recalls/safety campaigns and pairs with the title 'NHTSA recalls for a vehicle'. The 'specifically about recalls' phrasing implicitly separates it from sibling get_known_issues, but the description never states the verb/return explicitly, leaning on the name and title.

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?

'Use when the user asks specifically about recalls or safety campaigns' gives a clear trigger condition, and 'Requires exact slugs from resolve_vehicle' documents the prerequisite. It stops short of naming the alternative sibling (get_known_issues) or stating when NOT to use it.

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