generate_text_to_video

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It does well by mentioning the cost implication ('may incur costs'), specifying that it makes an API call to Vidu, and providing important behavioral details like default values, value ranges, and model-specific constraints. However, it doesn't mention rate limits, authentication requirements, or error handling.

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 well-structured with clear sections (purpose, cost warning, parameters, returns) and efficiently conveys necessary information. While comprehensive, some sentences could be more concise (e.g., the resolution section has repetitive model/duration combinations). Overall, most sentences earn their place by adding value.

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?

For a complex tool with 9 parameters, no annotations, and no output schema, the description does remarkably well. It covers the core functionality, cost implications, detailed parameter semantics, and return values. The main gap is the lack of output schema explanation - while it mentions 'task_id and video_url', it doesn't describe their format or how to use them. Given the complexity, it's quite complete but not perfect.

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?

Given that schema description coverage is 0% (no parameter descriptions in the schema), the description compensates excellently by providing comprehensive parameter documentation. It explains each parameter's purpose, default values, acceptable values, model-specific constraints, and important behavioral notes (like BGM only working with 4-second videos). This adds substantial meaning beyond the bare schema.

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 purpose: 'Generate a video from a prompt.' This is a specific verb+resource combination that indicates what the tool does. However, it doesn't explicitly differentiate from sibling tools like 'generate_img_to_video' or 'generate_template_to_video' which suggests similar video generation from different inputs.

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 excellent usage guidance with the 'COST WARNING' section that explicitly states when to use the tool ('Only use when explicitly requested by the user') and warns about potential costs. This gives clear context for appropriate usage, though it doesn't mention specific alternatives among the sibling tools.

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