price_insight

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

With no annotations provided, the description must carry the burden of behavioral disclosure. It mentions the tool is free, uses free comparable listings, and derives a price band with percentiles, which adds some transparency about the method and data source. However, it does not disclose whether the operation is read-only, whether it requires authentication, or what happens if no comparables are found—gaps that are significant for a tool with no annotations.

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 exceptionally concise at two sentences, with the core purpose front-loaded and no filler words. Every clause earns its place by contributing either the method, the differentiator (free vs. paid), or the optional behavior. It is a model of efficient communication.

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 that there is no output schema and no annotations, this description leaves out substantial operational details. It does not explain the output format (e.g., the structure of the price band or the verdict on a target price), how errors or edge cases (like zero comparables) are handled, or whether state and year filters significantly affect the results. An agent would likely need additional information to call this tool confidently and interpret its response.

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 input schema provides 100% coverage for all six parameters, so the description adds minimal value beyond what the schema already states. It does reinforce that the band is based on same make/model/year, which loosely maps to the year parameters, and mentions the optional 'targetPrice' judgment, but these are essentially restatements of the schema descriptions. With high schema coverage, a baseline 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 the tool's purpose: deriving a fair-price band from comparable listings, with the option to judge a target price. It distinguishes itself from search tools by focusing on valuation rather than listing retrieval, and it openly notes it avoids paid services like RedBook/CarHistory, setting it apart from potential alternatives.

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?

There is no explicit guidance on when to use this tool versus the many search tools in the sibling list (e.g., search_cars, search_all_cars). The description implies it is for pricing questions, but it does not state when a user query should route here rather than to a search tool, nor does it mention any exclusions or prerequisites.

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