Vehicle Database MCP Server

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 mentions the tool's function (error detection and suggestion) and constraints (year range, digit length), but doesn't describe what happens when errors are detected, how suggestions are presented, whether this is a read-only operation, or any rate limits or authentication requirements. For a tool with no annotation coverage, this leaves significant behavioral 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 appropriately concise with three sentences that each serve a purpose: stating the core functionality, specifying coverage, and stating support constraints. It's front-loaded with the main purpose. However, the second sentence could be more smoothly integrated, and there's some minor grammatical awkwardness ('This API supports VIN from year').

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 (error detection and correction), no annotations, no output schema, and 100% schema coverage for a single parameter, the description provides basic completeness but has significant gaps. It covers what the tool does and some constraints, but doesn't explain the output format, error handling, or how suggestions are structured, which would be important for an agent to use it effectively.

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 its single parameter ('vin'), so the schema already documents it adequately. The description doesn't add any parameter-specific information beyond what's in the schema. According to scoring rules, when schema_description_coverage is high (>80%), the baseline is 3 even with no param info in the description.

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: 'detects the error in the VIN digits and provides suggestions for the correct VINs including year, make and model.' It specifies the verb (detects error, provides suggestions) and resource (VIN digits), but doesn't explicitly differentiate from sibling tools like 'vin_decode' or 'decode_by_vin' which might 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 some usage context by specifying coverage (VINs from 1982-present) and support (17-digit VINs), which implies when to use this tool. However, it doesn't explicitly state when to choose this tool over alternatives like 'vin_decode' or 'decode_by_vin', nor does it mention prerequisites or exclusions beyond the year and digit constraints.

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