capcut_add_effect

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

No annotations are provided, so the description carries the full burden. It discloses that the call is dry-run by default and that real writes require CapCut to be closed, and it notes both example resources are free. It says nothing about what happens if the effects track is missing, whether an existing effect is replaced, or what the dry-run plan returns.

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 action and target, then the two modes and examples, ending with the dry-run default. Dense but every clause carries information; slightly overpacked with example IDs, though those earn their place given the opaque numeric resource_id format.

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 9-parameter, nested-object mutation tool with no annotations and no output schema, the description covers the core action and the most confusing parameter but omits the return shape of the dry-run plan, failure modes, and the role of `name`/`track`. Adequate but with clear gaps.

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?

With only 44% schema description coverage across 9 params, the description usefully compensates: it maps `kind` to CapCut concepts, gives concrete resource_id examples with names, and 'over a time range' frames start_s/duration_s. It still leaves `name` and `track` unaddressed in prose, but adds real meaning beyond the schema for the highest-risk parameters.

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 ('Add a CapCut video effect on an effect track over a time range') and immediately pins down the two modes, scene (video_effect) vs body (face_effect, follows people). This distinguishes it from siblings like capcut_add_filter, capcut_add_animation and capcut_add_transition without the agent needing to open other schemas.

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 clarifies which `kind` to pick and why (scene is a video effect, body follows people), and notes the operation is dry-run by default. It never says when to prefer this tool over capcut_add_filter or capcut_add_animation, nor what prerequisites (existing draft, CapCut closed) select it. Usage is implied rather than directed.

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