Vehicle Database MCP Server

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It mentions coverage years and regions but omits critical details: what data is returned (e.g., vehicle specs), whether it's a read-only operation, error handling, rate limits, or authentication needs. This leaves the agent with insufficient information to invoke the tool safely and effectively.

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 concise with two brief phrases, but it's under-specified rather than efficiently informative. It wastes space on tautological elements (e.g., 'CAD' in the name) instead of front-loading actionable details, making it less helpful despite its brevity.

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?

Given the complexity of VIN decoding and the lack of annotations and output schema, the description is severely incomplete. It fails to explain what the tool returns, error conditions, or behavioral traits, leaving the agent without enough context to use the tool correctly in a real-world scenario.

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%, with the single parameter 'vin' documented in the schema. The description adds no parameter-specific information beyond what the schema provides (e.g., format requirements, validation rules). According to the rules, with high schema coverage, the baseline score is 3, as the description doesn't compensate but doesn't need to heavily.

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 'Coverage: 1981- 2026 Support: CAD and US regions' is vague and tautological—it restates the tool name 'cad_decode_by_vin' without specifying what the tool actually does (e.g., decode VINs for Canadian and US vehicles). It fails to distinguish from siblings like 'by_vin', 'decode_by_vin', or 'us_decode', leaving the agent guessing about its unique function.

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?

No guidance is provided on when to use this tool versus alternatives. With many sibling tools (e.g., 'by_vin', 'us_decode', 'decode_by_vin'), the description offers no context, exclusions, or prerequisites, making it impossible for an agent to choose appropriately among them.

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