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

Annotations already cover read-only, idempotent, closed-world, and non-destructive behavior. The description adds useful context beyond that: free, no query-count deduction, source types, two-step selection, and explicit limits about prices and inventory.

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 paragraph is compact and front-loads the return scope, then workflow, exclusions, and cost. The cost point is split across 免费 and 选车不扣查询次数, a minor redundancy, but overall efficient.

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?

No output schema exists, and the description does explain the two-stage return of years then trims. However, for a nested input object with many filters and required enum fields, it leaves parameter usage and return structure underspecified.

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% and the description does not explain the nested query fields, including required model_id, business_type, and price_kind, or optional city, trim, mileage, and year filters. The mention of 年款 and 配置 only loosely hints at model_year and trim and does not compensate for the documentation gap.

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 states the tool returns model years and trims from recent records, public references, and catalog, and explicitly limits it to vehicle selection with no prices. That scope distinguishes it from quote-oriented siblings such as search_quotes and compare_quote.

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?

It gives a clear workflow: show model years first, then read full trims for the selected year, and it excludes pricing and proof of local inventory or recent quotes. It does not name the alternative sibling tools to use when pricing is needed.

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