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 'US/CAD region' but gives no details on what the tool does (e.g., read-only vs. mutation, data returned, error handling, rate limits, or authentication needs). For a tool with unknown behavior and no structured hints, this is a critical gap.

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 overly concise to the point of under-specification—'Support: US/CAD region' is a fragment that fails to convey essential information. While brief, it lacks structure and front-loads no useful details, making it inefficient rather than succinct. Every sentence should earn its place, but this one adds minimal value.

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 implied by sibling tools (e.g., decoding, checks) and no annotations or output schema, the description is incomplete. It doesn't explain what the tool returns, its behavior, or how it differs from similar tools. For a tool in a crowded namespace with no structured support, this leaves the agent without necessary 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?

The input schema has 100% description coverage, with the 'vin' parameter documented as a string (though the example is empty). The description adds no meaning beyond the schema—it doesn't clarify VIN format, validation, or regional constraints. With high schema coverage, the baseline is 3, as the schema handles parameter documentation adequately.

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 'Support: US/CAD region' is vague and tautological—it restates the name 'by_vin' without specifying what the tool does (e.g., decode VINs, check vehicle data). It mentions a region but lacks a clear verb+resource statement. Compared to siblings like 'decode_by_vin' or 'vin_decode', it fails to distinguish its purpose, leaving the agent guessing.

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., 'decode_by_vin', 'cad_decode_by_vin', 'us_decode'), the description offers no context, exclusions, or prerequisites. This forces the agent to infer usage from the name alone, which is insufficient for effective tool selection.

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