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. It describes the calculation purpose but lacks details on rate limits, accuracy of estimates, whether it requires user authentication, or what the output format looks like (e.g., structured data vs. text). This is a significant gap for a tool with financial implications.

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 and key inputs without unnecessary words. Every element earns its place, making it easy to scan and understand quickly.

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 5 parameters, 100% schema coverage, and no output schema, the description is minimally adequate. It covers the purpose but lacks behavioral context (e.g., output format, error handling) and deeper usage guidelines. Given the financial nature and no annotations, more completeness would be beneficial.

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. The description lists key parameters but does not add meaningful semantics beyond what the schema provides (e.g., explaining relationships between parameters or calculation logic). Baseline 3 is appropriate when the schema does the heavy lifting.

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 ('Calculate estimated monthly payment and financing options'), the resource ('for a vehicle on Carvana'), and the key inputs (price, down payment, credit score tier, loan term). It distinguishes itself from sibling tools like 'search_by_budget' or 'get_trade_in_value' by focusing on financing calculations rather than search or valuation.

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 when estimating financing for a vehicle purchase, but does not explicitly state when to use this tool versus alternatives like 'search_by_budget' (which might also involve budget constraints) or 'get_trade_in_value' (which provides a related input). No guidance on prerequisites or exclusions is provided.

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