Generate Video (Jimeng Video 3.0)

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

Annotations flag openWorldHint and non-idempotent write behavior, and the description adds substantial context beyond them: it is an asynchronous submit (returns task_id), it requires a first-frame image, output is 720P at 5s/10s, and the constraint that either image_url or image_base64 must be supplied. This is rich disclosure relative to what the structured fields already carry.

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?

Front-loaded with the model identity and input/output summary, then a clean Args list, a note, and two bilingual examples that earn their place. There is minor duplication of image constraints between the description and the schema, but overall it is well-organized rather than padded.

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?

With no output schema, the description carries the return burden and does so ('Returns: task_id'), and it covers the required alternate image inputs, output format, and the query follow-up. Nothing an agent needs to invoke it correctly is missing.

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 baseline is 3, but the description adds meaning: it maps frames values to seconds (121=5s, 241=10s), notes the seed default of -1 for reproducibility, and crucially states 'Either image_url or image_base64 must be provided (one of the two)' – a constraint the schema does not express since only prompt is marked required.

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?

States a specific verb+resource ('Submit a video generation task') plus the model (Jimeng Video 3.0) and clarifies it is an image-to-video first-frame model. It routes the agent to the sibling that retrieves results ('task_id for querying results with jimeng_query_video_task'), so the agent can distinguish it from its query counterpart without opening the schema.

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 workflow context is clear: submit here, then poll with jimeng_query_video_task, and the input requirements (first-frame image + motion prompt) tell the agent when this applies. However, it never contrasts the async submit against the sibling jimeng_generate_video_and_wait, leaving the agent to infer when to wait instead of polling.

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