Set an After Effects layer’s inPoint, outPoint, or duration and optionally slide it by adjusting startTime, using layer name or index and the active or named comp.
After Effects: set a layer inPoint/outPoint (or duration) and/or startTime (slides the layer).
| Name | Required | Description | Default |
|---|---|---|---|
| layer | Yes | Layer name or 1-based index. | |
| inPoint | No | ||
| duration | No | ||
| outPoint | No | ||
| startTime | No | ||
| compositionName | No | Comp name; omit to use the active comp. |
Changes observed during successful MCP inspections.
v1.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=false and destructiveHint=false, so the safety profile is covered. The description adds the useful note that startTime 'slides the layer', but it is silent on units, precedence when duration and outPoint are both supplied, and whether trimming clips existing keyframes.
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?
A single front-loaded sentence with no filler; the app prefix and the field grouping are both useful. It is arguably too compressed for a six-parameter mutation tool, but there is no wasted text.
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 mutation tool with 6 params, no output schema, and only 33% schema coverage, the definition leaves real gaps: units, interaction with keyframes/time remapping, and what the tool returns are all unaddressed. Adequate to identify the tool, not fully sufficient to call it confidently.
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 only 33%, so the description must carry four numeric parameters. It does gloss them meaningfully — duration as an alternative to in/out points, startTime as a slide — which is real added value, but units (seconds vs frames) and conflict resolution between duration and outPoint remain undocumented.
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 gives a specific verb ('set') plus the exact resources affected (inPoint/outPoint/duration/startTime) and names the host app. An agent can distinguish it from coverage-oriented siblings like ae_timeStretch or ae_timeRemap, though it does not explicitly say how it differs from them.
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 'or' construction clarifies the choice between trimming via inPoint/outPoint and duration, and that startTime is a separate sliding operation. However there is no guidance on when to prefer this over ae_timeStretch, ae_timeRemap, or ae_setTransform, and no stated prerequisites.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.