setLayerExpression · After Effects MCP Server MCP

WHAT IT DOES

What setLayerExpression does on After Effects MCP Server

AI agents invoke setLayerExpression to trigger actions in After Effects MCP Server. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call — builds kicked off, notifications sent, workflows started.

WHY IT NEEDS A POLICY

Why setLayerExpression needs a policy

The tool name 'setLayerExpression' strongly implies setting an expression on an After Effects layer. In After Effects, expressions are JavaScript code that runs to drive property values. Setting a layer expression constitutes executing or injecting code into the application, which could have significant effects. However, the description is empty, so confidence is reduced.

From the tool's definition Tool name 'setLayerExpression' on an After Effects MCP server that includes tools like 'run-script' and 'execute' capabilities

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

setLayerExpression Rate-limited

setLayerExpression stays usable, but rate-capped — a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "setLayerExpression": {
      "limits": [
        {
          "counter": "setlayerexpression_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

RATE-LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches After Effects MCP Server, so you can run agents against it safely.

FAQ

Questions about setLayerExpression

What does the setLayerExpression tool do? +

setLayerExpression. It is categorised as a Execute tool in the After Effects MCP Server MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on setLayerExpression? +

Register the After Effects MCP Server MCP server in PolicyLayer and add a rule for setLayerExpression: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches After Effects MCP Server. Nothing to install.

What risk level is setLayerExpression? +

setLayerExpression is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.

Can I rate-limit setLayerExpression? +

Yes. Add a rate_limit block to the setLayerExpression rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.

How do I block setLayerExpression completely? +

Set action: deny in the PolicyLayer policy for setLayerExpression. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.

What MCP server provides setLayerExpression? +

setLayerExpression is provided by the After Effects MCP Server MCP server (rtx1025189518-source/mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.