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

With no annotations provided, the description carries the burden of behavioral disclosure. It states the action and return, which is helpful, but does not disclose details like result ordering, how filters combine (AND/OR), inclusivity of min/max values, or any authentication/rate-limit requirements. Lacks depth but is not misleading.

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?

Two sentences, no redundancy. The first sentence states the core function and scope, the second lists filter dimensions and return value. Every word contributes to understanding.

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?

The tool has 15 parameters, no required fields, and no output schema. The description adequately conveys the high-level purpose but leaves gaps such as default sorting, whether location refers to dealer or vehicle location, and what 'dealer info' includes. Given the complexity, a complete description would provide more operational context, but the core is covered.

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 covers 100% of the parameters with descriptions, so the baseline is 3. The description's mention of filter categories (make, model, etc.) adds little beyond the schema, and it does not explain parameter interactions or default behaviors that the schema omits.

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 a specific verb ('search'), the resource ('used car inventory'), and the scope ('across all dealers'). It also lists the filter dimensions and the return value ('matching vehicles with dealer info'), distinguishing it from sibling tools like cars_dealer_inventory or cars_vehicle.

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?

The phrase 'across all dealers' implies a broad search use case, which contextualizes when to use it. However, it does not explicitly mention alternatives or when not to use it (e.g., when searching within a specific dealer, use cars_dealer_inventory). The usage guidance is implied rather than explicit.

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