下载生成的视频

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

Goes far beyond the annotations: discloses directory creation, no-overwrite policy, 512 MB stream cap, 90-second network deadline, partial-file cleanup on failure, and constrained key forwarding across redirects. This is exactly the operational context an agent needs for a write-to-disk tool.

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?

Densely front-loaded: purpose first, then return shape, then the write/overwrite/size/timeout constraints in short declarative clauses. No sentence is wasted.

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 two-param write tool with annotations and full schema coverage, the description covers return values (path, bytes, mime), limits, failure behavior, and auth handling. 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 both parameters are already documented with the same .mp4/absolute/not-exist semantics. The description reinforces but does not materially extend parameter meaning beyond what the schema provides, matching the baseline for high coverage.

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 (Download) and resource (a succeeded task as an MP4) plus the destination (an absolute local output path). This makes it distinguishable from seedance_get_video, which would return info rather than write a file to disk.

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 phrase 'a succeeded task' establishes a clear precondition for use, and the disk-write behavior implies when this is appropriate. However, it never explicitly names an alternative (e.g., get_video) or states 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.