MCP Carvana

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

No annotations are provided, so the description carries full burden for behavioral disclosure. It mentions 'including financing assumptions,' which hints at backend calculations, but doesn't explain what 'best vehicles' means (e.g., ranking criteria), whether results are filtered or sorted, if there are rate limits, or what the output format looks like. For a tool with 6 parameters and no output schema, this leaves significant gaps.

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, efficient sentence that front-loads the core purpose. It avoids redundancy and wastes no words, though it could potentially benefit from slightly more detail given the tool's complexity.

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 tool with 6 parameters, no annotations, and no output schema, the description is insufficient. It doesn't explain the output format, how 'best' is determined, error conditions, or behavioral traits like whether it's a read-only search or has side effects. The high parameter count and lack of structured metadata require more descriptive context.

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 100%, so the schema already documents all parameters thoroughly with descriptions and enums. The description adds marginal value by implying that parameters like 'monthly_budget' and 'down_payment' are used together in financing calculations, but doesn't provide additional syntax, constraints, or interaction details beyond what's in the schema.

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: 'Find the best vehicles on Carvana that fit within a monthly payment budget, including financing assumptions.' It specifies the action (find), resource (vehicles on Carvana), and key constraint (monthly payment budget). However, it doesn't explicitly differentiate from sibling tools like 'search_vehicles' or 'get_financing_estimate,' which could have overlapping functionality.

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 provides no guidance on when to use this tool versus alternatives. With multiple sibling tools like 'search_vehicles,' 'compare_vehicles,' and 'get_financing_estimate,' there's no indication of specific scenarios, prerequisites, or exclusions for this budget-focused search tool.

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