Bulk-set multiple keyframes in After Effects with a single call to build motion efficiently. Specify layer, property, time, value, and easing for each keyframe.
After Effects: bulk-set many keyframes in one call (cheapest way to build motion). keys: [{layer, property, time, value, ease?, easeIn?, easeOut?, interpolation?}].
| Name | Required | Description | Default |
|---|---|---|---|
| keys | Yes | ||
| 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 this is a non-read-only, non-destructive, closed-world mutation. The description adds that it is a bulk operation and efficient for motion building, but it does not explain what happens to existing keyframes, whether it overwrites at matching times, or what state the active comp must be in.
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 short, front-loaded, and wastes no space. It states the bulk-set purpose immediately and follows with the key object shape in a single compact sentence.
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 nested bulk mutation tool with no output schema, the description omits important context such as time units, property naming, overwrite behavior, and ordering/atomicity semantics. Annotations cover the safety profile, but the agent still lacks enough detail to call this confidently in non-trivial 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?
The description lists the keyframe object fields including optional ease and interpolation fields, which gives a quick shape reference. However, it adds little semantic meaning beyond the schema and provides no units for time, no property path syntax, and no explanation of compositionName.
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 states a specific verb and resource: bulk-setting many After Effects keyframes in one call. It implicitly distinguishes itself from the singular ae_setKeyframe by emphasizing bulk operation, though it does not name the sibling explicitly.
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?
It implies usage for bulk keyframe creation and calls this the 'cheapest way to build motion,' but gives no explicit when-not guidance or named alternatives. An agent can infer it should use this for multiple keyframes rather than single-key operations.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.