capcut_add_video

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

With no annotations, the description carries the full behavioral burden. It usefully discloses that the edit is session-scoped and only becomes permanent after calling capcut_save, which is a critical operational fact. It does not disclose other behavioral traits such as whether existing clips are replaced, whether validation occurs, or what happens on failure.

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 two short sentences with no filler. The core action is front-loaded, and the session-save caveat is the second, equally important fact. Every phrase earns its place.

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 14-parameter, no-annotation, no-output-schema mutation tool, this description is too thin. It gives a valuable save instruction but lacks guidance on parameter dependencies, defaults, sibling tool selection, or preconditions, making it insufficient for an agent to invoke the tool correctly in all cases.

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 only 36%, so the description needed to compensate for the 14 parameters, but it adds almost nothing. 'video clip' faintly implies the file parameter should be a video file, and 'track' hints at trackIndex, but required parameters like draft are left unexplained and no defaults or unit details are provided beyond the sparse schema.

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 identifies a precise action ('add a video clip') and a specific resource ('a track'). The word 'video' clearly differentiates this from sibling add_* tools such as capcut_add_image, capcut_add_audio, and capcut_add_text, and 'at a time' signals it is not a batch operation.

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 description conveys implied usage context: use this tool to place a single video clip on a track. 'Session edit; call capcut_save to persist' also tells the agent that persistence requires a later capcut_save call. However, it does not explicitly state when not to use it, name alternatives, or mention prerequisites like draft validity.

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