Video Screenshot MCP

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. While '验证' (validate) implies a read-only check, the description doesn't specify what '有效且支持处理' (valid and supports processing) means operationally - whether it checks format compatibility, file integrity, encoding support, or other criteria. No information about error conditions, performance characteristics, or output format is provided.

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 a single, efficient Chinese sentence that states the core purpose without unnecessary words. While appropriately concise, it could be slightly more structured by separating the validation purpose from the criteria being checked, but it's well within acceptable bounds for a simple tool.

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 validation tool with no annotations and no output schema, the description is insufficient. It doesn't explain what constitutes '有效且支持处理' (valid and supports processing), what validation criteria are applied, what the output looks like (success/failure, detailed diagnostics), or how this differs from simply checking file existence. The agent lacks critical context to 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?

The schema has 100% description coverage with 'videoPath' clearly documented as '视频文件路径' (video file path). The description doesn't add any parameter-specific information beyond what the schema provides, such as path format requirements or supported video locations. With complete schema coverage, the baseline score of 3 is appropriate.

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 as '验证视频文件是否有效且支持处理' (validate video file for validity and processing support), which is a specific verb+resource combination. However, it doesn't explicitly distinguish this validation tool from its siblings like 'get_video_info' which might provide similar information, keeping it from a perfect score.

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 no guidance on when to use this tool versus alternatives. It doesn't mention prerequisites, timing considerations, or how it differs from sibling tools like 'get_video_info' which might also provide validation-related information. This leaves the agent without contextual usage direction.

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