Add a null control layer to any After Effects composition by specifying the target composition and layer name. Use null layers to drive expressions, parenting, or animations.
Add a null (control) layer to a composition
| Name | Required | Description | Default |
|---|---|---|---|
| comp_name | Yes | Target composition name | |
| layer_name | Yes | Name for the null layer |
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 full responsibility for behavioral disclosure. It only states the basic action without revealing side effects, such as where the null layer is placed in the layer stack, whether it appears in rendering, or what happens if the composition already has a layer with the same name. This is a meaningful gap for a mutation 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?
The description is a single, front-loaded sentence with no wasted words. The main action and resource are stated immediately, and the control-layer clarification is included parenthetically without bloating the 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 two-parameter tool with no output schema and no annotations, the description is adequate but thin. It does not explain behavioral consequences or provide routing guidance, though the simplicity of the operation partially offsets this. An agent can call it correctly, but may miss important contextual expectations.
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 the target composition name and the null layer name. The description adds no further parameter-level semantics beyond echoing 'composition' and 'layer'.
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 uses a specific verb ('Add'), resource ('null (control) layer'), and target ('a composition'), clearly distinguishing it from siblings like ae_add_text_layer, ae_add_solid_layer, and ae_add_shape_layer. The parenthetical 'control' adds useful semantic context.
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 implies usage when a null/control layer is desired, but it does not explicitly state when to prefer this tool over alternatives or mention any preconditions, such as the composition needing to exist. The guidance is implied by the resource type rather than stated.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.