Get the full history of a vehicle by VIN — every dealer it appeared at, price changes over time, days on market, whether it was sold and resurfaced elsewhere. Data with origin.
| Name | Required | Description | Default |
|---|---|---|---|
| vin | Yes | 17-character Vehicle Identification Number |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden. It discloses the response scope (full history, dealer appearances, price changes, etc.) and adds 'Data with origin' suggesting provenance. The verb 'Get' implies a read-only operation, and no side effects are indicated. However, it does not mention rate limits, authentication, or potential response limitations.
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 a single, information-dense sentence that front-loads the action ('Get the full history') and then lists specific data points. Every part adds value, with no redundant or filler content. The trailing 'Data with origin' is terse but informative.
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 single-parameter lookup with no output schema, the description sufficiently explains what the tool does and what the response contains (dealer appearances, price changes, days on market, resurfacing). It does not detail return structure or edge cases, but the core purpose and output are clear enough for an agent to invoke it correctly.
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 schema description coverage is 100%: the single 'vin' parameter is described as '17-character Vehicle Identification Number'. The description adds no additional parameter semantics or format details beyond what the schema already provides, so the baseline score 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 specific action and resource: 'Get the full history of a vehicle by VIN'. It enumerates the exact data included: dealer appearances, price changes, days on market, and whether it sold and resurfaced, which differentiates it from sibling tools like cars_vehicle that likely provide current vehicle info.
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 description implies its use for historical vehicle data ('full history') but provides no explicit when-to-use or when-not-to-use guidance, nor does it mention alternatives among sibling tools. Usage is inferred from the content rather than explicitly stated.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Add one secure layer between your agents and this server.
Most tools target distinct resources (dealer inventory, vehicle search, session actions), but cars_session_message and cars_session_reply have overlapping purposes as both involve posting messages. The session tools are otherwise clearly differentiated by their action verbs.
All tools share the 'cars_' prefix and use snake_case, but the verb-noun pattern is inconsistent: some are action-first (cars_search, cars_session_create) while others are noun-only (cars_vehicle, cars_dealers, cars_history). Session tools follow a consistent 'session_<verb>' structure, but the broader set mixes conventions.
With 19 tools, the set is on the heavy end, falling in the 16-25 range that feels borderline. The count is justified by the comprehensive session workflow, but it approaches the threshold where tool selection becomes cumbersome.
The core journey of searching, inspecting, and tracking vehicles through sessions is well covered, including dealer communication and trade-in. However, there are notable gaps: no way to remove a vehicle from a session or update general buyer profile details (payment method, timeline) after initial creation.