veo_extend

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

No annotations provided, and the description does not disclose behavioral traits such as whether the original video is modified, permissions needed, output format, or error handling. The description carries full burden and fails to inform.

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?

Two sentences with clear front-loaded purpose. No extraneous content. However, key information is missing, reducing the value of conciseness.

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 no output schema, no annotations, and moderate complexity (6 params, many siblings), the description is incomplete. It lacks details on expected output, duration, effect on original, and error scenarios.

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 description coverage is 67% (4 of 6 parameters described in schema). The description adds no additional parameter context beyond the prerequisite. It does not explain the meaning of 'prompt', 'model', 'seeds', 'filename', or 'download_dir' in relation to the extension process.

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 extends an existing Veo 3.1 video with additional content, specifying the prerequisite (taskId). It distinguishes from generation tools but does not explicitly differentiate from other extension tools like runway_extend.

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?

Only mentions the prerequisite of having a taskId from a previous Veo generation. No guidance on when to use this tool over alternatives (e.g., generate_video, runway_extend) or when not to use it.

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