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

Goes well beyond the annotations (which only say readOnly=false, destructive=false, openWorld=false) by disclosing the 30-minute validity window, the ten-file cap, and that it costs no credits. It also describes the required human-in-the-loop interaction sequence, which is essential behavioral context.

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 purpose, then limits, workflow, and trigger. Dense and mostly waste-free, though the four-item file-type example list is slightly long for what it conveys.

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 an output schema present, return values need no explanation, and the description covers the trigger, the constraints, the handoff to list_uploads, and the cost. Nothing an agent needs to invoke this 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 optional parameters (note, purposes) are already fully documented. The description's list of file kinds loosely maps to the purposes enum but never references the parameters by name or adds syntax beyond the schema, so the baseline 3 applies.

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 and resource: it returns a link to a ClipUGC page where the user drops files. The concrete file-type examples (screen recording, reference photo/video, music) make it unmistakable versus siblings like generate_image or make_video.

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?

Explicit trigger ('use it whenever the user has a file on their device and no https link for it') plus a named follow-up workflow (call list_uploads, then pass ids to recording_upload/photo_upload/driver_upload/music_upload). When-to-use and the alternative path are both spelled out.

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