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 the tool 'returns' data and is 'comprehensive and accurate', but lacks details on error handling, rate limits, authentication needs, response format, or whether it's read-only or has side effects. For a tool with no annotations, this leaves significant behavioral gaps, though it does specify coverage and target audience.

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 three sentences long and front-loaded with the core purpose, but includes some marketing language ('designed for customers and businesses', 'deliver a complete picture') that doesn't add operational value. It could be more concise by focusing strictly on functional details, though it's not excessively verbose.

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 tool's moderate complexity (single parameter, no output schema, no annotations), the description provides basic purpose and scope but lacks details on behavior, output structure, and differentiation from siblings. It's minimally adequate for a simple lookup tool but doesn't fully address the context needed for optimal agent use, especially without annotations or output schema.

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 input schema has 100% description coverage for the single parameter 'vin', including an example. The description doesn't add any parameter-specific information beyond what's in the schema, such as VIN format requirements or validation rules. With high schema coverage, the baseline is 3, as the description doesn't compensate but also doesn't detract.

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: 'USA VIN decode is built to return a wide range of data points' and 'returns comprehensive and accurate VIN descriptions, packages information, and more.' It specifies the verb ('decode'), resource ('VIN'), and scope ('USA', '1981-present'), distinguishing it from some siblings like 'eu_decode' or 'motorcycle_decode'. However, it doesn't explicitly differentiate from similar tools like 'by_vin', 'vin_decode', or 'universal_vin_decode', which slightly reduces clarity.

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: 'designed for customers and businesses in need of complete vehicle specifications, features, and equipment' and 'Coverage: 1981-present', suggesting it's for detailed USA vehicle data. However, it doesn't explicitly state when to use this tool versus alternatives like 'by_vin' or 'vin_decode', nor does it provide exclusions or prerequisites. The guidance is present but not comprehensive.

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