API-Market MCP Server

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

With no annotations provided, the description carries full burden for behavioral disclosure but fails completely. It doesn't indicate this is a mutation/write operation (face swapping modifies images), doesn't mention authentication requirements, rate limits, output format, error conditions, or any behavioral characteristics. The description is purely technical implementation details.

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 technically concise (one sentence) but under-specified rather than efficiently informative. It wastes its single sentence on implementation details (POST request path) rather than conveying purpose or usage. While brief, it fails to use its limited space effectively.

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 face-swapping tool with no annotations and no output schema, the description is completely inadequate. It doesn't explain what the tool does, when to use it, what behavior to expect, or what the output will be. The description fails to provide the minimal context needed for an AI agent to understand and use this tool 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?

Schema description coverage is 100%, with both parameters clearly documented as requiring 'an image with a face'. The description adds no additional parameter information beyond what's in the schema, so the baseline score of 3 is appropriate since the schema does the heavy lifting for parameter documentation.

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 'Make a POST request to capix/faceswap/faceswap/v1/image' is tautological - it restates the tool's name 'ImageFaceSwap' as a generic HTTP action without specifying what the tool actually does. It doesn't explain that this tool swaps faces between two images, nor does it differentiate from sibling 'VideoFaceSwap' which handles video instead of images.

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 about when to use this tool versus alternatives. The description doesn't mention that this is for image face swapping specifically (versus video face swapping), nor does it provide any context about appropriate use cases, prerequisites, or limitations.

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