video_mix

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 only states a high-level purpose and fails to mention async behavior, model selection, potential side effects, or output format. For a video generation tool, this is a significant transparency 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 a single, short sentence with no redundancy or filler. It is front-loaded and easy to parse. It is appropriately concise, though it sacrifices detail for brevity, which is a minor drawback but not a structural issue.

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?

With 8 parameters and no output schema, the description is insufficient for complete contextual understanding. It does not mention return values, how to handle async mode, or required prompt syntax. The description relies entirely on the schema, which is rich but still leaves the agent without high-level context about the workflow.

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 covers 100% of the parameters, so the baseline is 3. The description adds minimal semantic context by referencing 'multiple images' (referenceImages) and 'one scene' (prompt), but it does not explain the [图N] syntax or other parameter constraints. It stays at baseline.

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 function: merging subjects from multiple images into one scene. This is a specific verb+resource combination that conveys the core purpose. However, it does not differentiate from sibling tools like video_multi, which likely has a similar function, so it loses one point.

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 such as video, video_multi, or video_frame. There are no exclusions, prerequisites, or contextual examples, leaving the agent without direction for tool selection.

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