MCP Carvana

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

With no annotations provided, the description carries the full burden of behavioral disclosure. While it indicates this is a retrieval operation, it doesn't disclose important behavioral traits such as whether authentication is required, rate limits, error conditions, response format, or whether this is a paid service. The description provides basic functional information but lacks operational context needed for proper tool invocation.

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, well-structured sentence that efficiently communicates the tool's purpose and scope. Every element serves a purpose: the action, target, and specific data components. There's no redundant information or unnecessary elaboration, making it optimally concise for its informational content.

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 read-only data retrieval tool with 2 parameters and no output schema, the description provides adequate functional context but lacks important operational details. Without annotations or output schema, the description should ideally address response format, error handling, or authentication requirements. It's minimally complete for basic understanding but leaves gaps for practical implementation.

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?

With 100% schema description coverage, the input schema already fully documents both parameters (stock_number and VIN). The description doesn't add any meaningful parameter semantics beyond what's in the schema - it doesn't explain parameter relationships, which parameter takes precedence, or provide usage examples. The baseline score of 3 reflects adequate but not enhanced parameter understanding.

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 ('Retrieve vehicle history report summary') and resource ('for a Carvana listing'), with explicit details about what information is included ('accident history, number of owners, service records, and title status'). It distinguishes itself from sibling tools like 'get_vehicle_details' by focusing specifically on historical data rather than current specifications.

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 usage context (when researching a Carvana vehicle's background) but doesn't explicitly state when to use this tool versus alternatives like 'get_vehicle_details' or 'get_market_insights'. No guidance is provided about prerequisites, exclusions, or specific scenarios where this tool is most appropriate versus other vehicle information tools.

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