add_watermark

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

No annotations exist, so the description must disclose behavior. It does not mention what happens if input_path is invalid, whether files are overwritten, processing time, or error handling. Very minimal behavioral information.

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 concise, with a single-sentence purpose followed by parameter list. It is front-loaded and contains no fluff, though parameter descriptions could be more detailed.

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?

No output schema or annotations, so the description should explain return values and side effects. It only says '添加结果信息' (add result info), which is vague. Missing error handling, default behavior details, and outcome for optional parameters.

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 0%, so the description must compensate. It provides basic descriptions for all 6 parameters (e.g., '输入视频文件路径' for input_path), adding some meaning beyond schema names, but lacks details on accepted formats, constraints, or interactions.

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 '为视频添加水印' (Add watermark to video), which is a specific verb+resource combination. Among siblings, no other tool adds watermarks, so it is distinct.

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 on when to use this tool vs alternatives, no prerequisites, limitations, or exclusions provided. The description simply lists parameters without usage context.

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