Apply a CapCut transition to a segment, creating a visual effect between it and the next clip on the same track.
Attach a real CapCut transition (from capcut_list_transitions) on this segment, applied between it and whichever segment follows immediately on the same track.
| Name | Required | Description | Default |
|---|---|---|---|
| name | Yes | ||
| draft | Yes | ||
| segmentId | Yes | ||
| durationSec | No | default: the transition's own default duration |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the burden of behavior. It adds non-obvious constraints: the name must be a real transition from capcut_list_transitions, and the effect is anchored to the immediately following segment on the same track. However, it does not disclose side effects on the draft, failure behavior when no following segment exists, or whether the change requires save/undo.
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?
One sentence, front-loaded with the core action and placement, no filler. 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?
The definition covers the main intent and the key prerequisite (list_transitions), and the output schema is absent so no return contract is promised. It lacks error/edge-case guidance and explicit origin of draft/segmentId, leaving the agent to infer some semantics from sibling tools.
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 describes only durationSec; the three required params are bare. The description compensates partially by defining name as a valid transition from list_transitions and segmentId as 'this segment' with a following segment on the same track. draft is left unexplained, so compensation is incomplete.
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 operation ('Attach') on a specific resource (a CapCut transition) and a precise placement (between this segment and the next on the same track). It is clearly distinct from sibling tools like add_filter or add_mask, and points to list_transitions as the source of valid transition names.
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 when it applies: adding a transition to a segment and getting the transition from capcut_list_transitions. It gives clear context but does not explicitly say when not to use it or mention alternatives.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.