generate_video

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

With no annotations, the description carries full responsibility. It discloses the async nature, long generation time (1-10 minutes), blocking wait behavior, and the ability to continue via get_video_status. It does not mention rate limits or authentication, but core behavioral traits are well 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?

The description is lengthy but well-structured: a brief summary, async behavior note, then a labeled Args list. Each parameter line is concise. No redundant fluff, though the length is justified given the number of parameters.

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 14 parameters and multiple model families, the description covers the async workflow, parameter semantics, and the relationship with get_video_status. An output schema exists, so return format details are not required. Minor gaps around error handling or prerequisites, but overall complete enough for correct selection and invocation.

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 0%, so the description fully compensates by explaining every parameter's meaning, constraints (e.g., duration 2-15, size '1280x720'), and model-specific differences (wan2.5/2.6 vs 2.7). This is comprehensive and directly actionable, exceeding schema expectations.

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?

Description explicitly states '视频生成：文生视频或图生视频', identifying the verb and resource clearly. It distinguishes from siblings like generate_image (image generation) and edit_image, and references get_video_status for querying, making the tool's scope unambiguous.

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?

Provides clear workflow guidance: default blocks until completion, and if timeout/interrupted, use get_video_status with the returned task_id. Parameter explanations also include context for choosing between text-to-video and image-to-video models. However, there is no explicit 'when not to use this tool' beyond inferring from alternatives.

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