create_blueprint · Unreal MCP: Risk & Policy

WHAT IT DOES

What create_blueprint does on Unreal

AI agents use create_blueprint 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 create_blueprint needs a policy

Creating a Blueprint class is a Write operation because it creates new data (a Blueprint asset) that can be modified or deleted later. It has moderate blast radius in that it could clutter the project with unwanted assets or interfere with development workflows, but the operation is reversible and doesn't execute arbitrary code or delete existing content.

From the tool's definition Tool name 'create_blueprint' and description 'Create a new Blueprint class' indicate creation of a new asset/class in Unreal Engine. This is a reversible modification operation.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

create_blueprint Rate-limited

create_blueprint 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": {
    "create_blueprint": {
      "limits": [
        {
          "counter": "create_blueprint_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 create_blueprint

What does the create_blueprint tool do? +

Create a new Blueprint class. 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 create_blueprint? +

Register the Unreal MCP server in PolicyLayer and add a rule for create_blueprint: 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 create_blueprint? +

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

Can I rate-limit create_blueprint? +

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

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

create_blueprint 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.