generate_video

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

Without annotations, the description fully discloses behavior: asynchronous (returns Task ID, needs polling), default values, accepted values for ratio and resolution, automatic role assignment for images, and model-specific limitations (e.g., generate_audio only for Pro models).

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?

Well-structured: starts with main purpose, then critical instructions in bold, followed by capabilities. Each sentence adds value without redundancy. Uses formatting for emphasis and lists for clarity.

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?

Fully covers all aspects needed for correct usage: explains the asynchronous workflow, all parameter constraints, mode-specific behaviors, and edge cases (e.g., seed for reproducibility, watermark option). With an output schema present, the description appropriately focuses on input semantics and process.

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?

Adds critical meaning beyond the input schema: clarifies that 'model' should be omitted unless user specifies an Endpoint ID, that 'ratio' must not use 'size' parameters, and explains the roles of image_urls, video_urls, and audio_urls for different modes. Enumerates accepted values for ratio explicitly.

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?

Explicitly states "Create a video generation task" and distinguishes from sibling tools by noting that this tool only submits the task and returns a Task ID, while `get_video_task_result` must be polled later.

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?

Provides clear when-to-use instructions: only for submitting tasks, not for retrieving results. Gives detailed do's and don'ts (e.g., use 'ratio' not 'size', leave 'model' empty unless custom endpoint). Lists three capability modes with their parameter requirements.

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