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 content), doesn't mention authentication requirements, rate limits, processing time, output format, or any side effects. The HTTP POST method hint is insufficient for an agent to understand the tool's behavior.

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?

While technically concise (one sentence), this is under-specification rather than effective brevity. The single sentence wastes its limited space on HTTP mechanics instead of explaining the tool's purpose. It's front-loaded with irrelevant technical details rather than user-facing functionality.

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 video processing tool with 2 required parameters, 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 format the output takes. The agent would struggle to use this tool correctly based solely on this description.

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%, so the schema already documents both parameters thoroughly with descriptions, patterns, and defaults. The description adds absolutely no additional parameter information beyond what's in the schema. This meets the baseline of 3 when schema does the heavy lifting, but earns no extra credit.

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/video' is a tautology that merely restates the tool's HTTP method and endpoint without explaining what the tool actually does. It fails to mention face swapping between video and image, which is only implied by the tool name 'VideoFaceSwap' and parameter descriptions. Compared to sibling 'ImageFaceSwap', it doesn't differentiate that this tool processes videos rather than 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?

The description provides zero guidance on when to use this tool versus alternatives. It doesn't mention the sibling 'ImageFaceSwap' tool for image-based face swapping, nor does it explain prerequisites like needing specific URL formats or file types. There's no context about appropriate use cases or limitations.

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