sc_checkout · Unreal MCP: Risk & Policy

WHAT IT DOES

What sc_checkout does on Unreal

AI agents use sc_checkout 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 sc_checkout needs a policy

Checking out files in source control modifies the state of the repository by locking or reserving files for editing. This is a reversible operation (files can be checked back in or reverted), so it falls under Write rather than Destructive.

From the tool's definition Tool name 'sc_checkout' and description 'Check out file(s) from source control' indicate modification of source control state. Checkout is a write operation that changes file locks/reservations in version control systems.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

sc_checkout Rate-limited

sc_checkout 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": {
    "sc_checkout": {
      "limits": [
        {
          "counter": "sc_checkout_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 sc_checkout

What does the sc_checkout tool do? +

Check out file(s) from source control. 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 sc_checkout? +

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

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

Can I rate-limit sc_checkout? +

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

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

sc_checkout 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.