apply_anim_modifier · Unreal MCP: Risk & Policy

WHAT IT DOES

What apply_anim_modifier does on Unreal

AI agents use apply_anim_modifier to create or update resources in Unreal — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Unreal environment.

WHY IT NEEDS A POLICY

Why apply_anim_modifier needs a policy

This tool modifies animation assets within Unreal Engine by applying modifiers to sequences. This is a reversible Write operation—the modification can be undone or changed. It's not Destructive because animation modifiers are non-destructive adjustments, not irreversible deletions. It's not Execute in the sense of arbitrary code execution, but rather a targeted asset manipulation.

From the tool's definition Tool applies (modifies) an animation modifier to an animation sequence. The verb 'apply' indicates a modification operation that changes animation asset state.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

apply_anim_modifier Rate-limited

apply_anim_modifier stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "apply_anim_modifier": {
      "limits": [
        {
          "counter": "apply_anim_modifier_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

LIMIT THIS TOOL →

Instant setup, no code required.

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

FAQ

Questions about apply_anim_modifier

What does the apply_anim_modifier tool do? +

Apply an animation modifier to an animation sequence. It is categorised as a Write tool in the Unreal MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on apply_anim_modifier? +

Register the Unreal MCP server in PolicyLayer and add a rule for apply_anim_modifier: 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 Unreal. Nothing to install.

What risk level is apply_anim_modifier? +

apply_anim_modifier is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit apply_anim_modifier? +

Yes. Add a rate_limit block to the apply_anim_modifier 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 apply_anim_modifier completely? +

Set action: deny in the PolicyLayer policy for apply_anim_modifier. 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 apply_anim_modifier? +

apply_anim_modifier is provided by the Unreal MCP server (sam-david/unreal-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.