Creates a null object layer in an After Effects composition for rigging, parenting, or animation controls. Use it to add control layers for animation setups.
Create a null object layer for rigging, parenting, or animation controls
| Name | Required | Description | Default |
|---|---|---|---|
| name | No | Null layer name (default: "Null 1") | |
| compName | No | Composition name | |
| duration | No | Duration in seconds (defaults to comp duration) |
Changes observed during successful MCP inspections.
v1.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full behavioral burden. It does not state which composition the null lands in, what happens when compName is omitted, whether the new layer becomes selected, or whether it is reversible — significant gaps for a mutating creation tool.
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 well-formed sentence that front-loads the verb and resource and uses the trailing clause to convey purpose. Nothing is wasted, though it stops short of the compactness-plus-routing of a 5.
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 zero-required-param creation tool with full schema coverage and no output schema, the essentials are covered. It still omits default-comp behavior and post-creation effects that an agent would need when calling it without arguments.
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 100%, so the schema already documents name, compName, and duration with their defaults. The description adds no parameter meaning beyond that, so the baseline 3 applies.
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 ('Create') plus a distinct resource ('null object layer') and even names the intent ('rigging, parenting, or animation controls'). The resource is clearly separable from siblings like createCamera, createTextLayer, or createSolidLayer, though it doesn't explicitly contrast itself with 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 phrase 'for rigging, parenting, or animation controls' gives implied usage context, so an agent can infer when a null is appropriate. However, there is no explicit when-not-to-use guidance and no routing to alternative layer-creation siblings, leaving selection mostly to inference.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.