After Effects MCP Server

by SUBSAHARXN

Overview Schema Source Related Servers Discussions Admin

JavaScript

Local

set-audio-levels

Adjust audio levels in dB for an After Effects audio or AV layer, with per-channel control and optional keyframes.

Instructions

Set the audio levels (in dB) for an audio or AV layer. Supports per-channel control and optional keyframing.

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "compIndex": "<compIndex>",
      "layerIndex": "<layerIndex>"
    },
    "name": "set-audio-levels"
  }
}

Input Schema

Name	Required	Description
`level`	No	Level in dB applied to both left and right channels (e.g. 0 = unity, -6 = half volume, -96 = silence).
`compIndex`	Yes	1-based composition index.
`leftLevel`	No	Left channel level in dB (overrides level for left channel).
`layerIndex`	Yes	1-based layer index.
`rightLevel`	No	Right channel level in dB (overrides level for right channel).
`timeInSeconds`	No	If provided, sets a keyframe at this time instead of a static value.

Schema Changelog

Changes observed during successful MCP inspections.

First observedv1.0.0Oct 17, 2026

TDQS

A3.8/5.0

Behavior3/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations, the description carries the burden. It discloses the dB unit, per-channel control, and keyframing capability, but it does not explain what happens if no level is provided, how left/right override level, or whether existing keyframes are replaced. This leaves gaps 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.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is a single, concise sentence that front-loads the action and resource, then adds two key feature areas. Every word earns its place with no redundancy or filler.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness4/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the 100% schema coverage and absence of an output schema, the description provides a sufficient high-level overview for an agent to select and invoke the tool. It lacks explicit usage exclusions and edge-case behavior, but the combination with the detailed schema is adequate.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100%, with each property already described in detail (e.g., leftLevel 'overrides level for left channel', timeInSeconds sets a keyframe). The description adds no additional parameter semantics, so the baseline of 3 is appropriate.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description uses a specific verb ('Set') with a clear resource ('audio levels (in dB) for an audio or AV layer') and scopes the behavior with 'per-channel control and optional keyframing'. This distinguishes it from sibling read tools like get-audio-info and other setters like set-effect-property.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines3/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description implies when to use the tool (when adjusting audio levels) but provides no explicit alternatives or exclusions. It does not reference sibling tools or state when not to use it, leaving the agent to infer usage from context.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.