Generate a video

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

With no annotations provided, the description carries the full disclosure burden and does so well. It reveals that the tool runs models on the user's own credits, many return sound in the same pass, an API key is required, and free accounts have specific model/resolution/duration limits.

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 three sentences with no wasted words. It front-loads the core purpose, then adds high-value details about models, sound, API key requirements, and free-tier limits without redundancy.

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 absence of annotations and output schema, the description is impressively complete: it covers input variants, auth, model selection, cost implications, and free-tier constraints. It could still mention async behavior or how to fetch results via get_task, but the schema's wait parameter partially covers that gap.

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 already covers all 8 parameters at 100% coverage, so the baseline is 3. The description adds meaningful parameter context by highlighting image_url for image-to-video and giving concrete constraints for the free account, like minimax-h3-fast with 480p/768p and 4–15 seconds.

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 opens with a specific verb and resource: 'Generate a video clip from a prompt, or animate a still by passing image_url.' This clearly distinguishes the tool's purpose from siblings like generate_image and edit_image by focusing on video output and including the image-to-video variant.

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?

It provides clear context for when to use the tool: whenever a video clip is needed, either from a prompt or from a starting image. It gives practical usage guidance, like passing model minimax-h3-fast on a free account and using image_url for image-to-video, but it does not explicitly name alternatives or exclude cases.

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