generate_video

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

Without annotations, the description carries the burden. It discloses the asynchronous nature ('without waiting for rendering'), implies poll-based workflow ('poll yourself with check_video'), and warns of credit consumption ('Consumes account credits'). It could add more on side effects/failure modes, but the key behaviors are covered.

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?

Three concise sentences: the first states the action and result, the second gives usage guidance with an alternative, and the third warns of cost. Every sentence earns its place, and the most important information is front-loaded.

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?

Given the tool's complexity (14 params, nested objects, no annotations, no output schema), the description + schema adequately inform an agent. The description clarifies when to use it and its async behavior, and the schema covers all parameter details. It lacks detailed return formatting or error handling, but states it returns video_id, which is sufficient.

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 coverage is 100%, so the schema thoroughly documents all 14 parameters. The description adds no parameter-specific semantics beyond what the schema provides, which aligns with the baseline of 3 for high schema coverage.

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 submits a video to HeyGen and returns the video_id immediately without waiting for rendering, which is a specific verb+resource+behavior. It also distinguishes itself from the sibling create_video, satisfying the requirement for differentiation.

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?

Explicit recommendations are given: use this only when polling with check_video is appropriate (e.g., very long videos), and use create_video otherwise. This is a clear when-to-use/alternative guidance.

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