sc_mark_for_add · Unreal MCP: Risk & Policy

WHAT IT DOES

What sc_mark_for_add does on Unreal

AI agents use sc_mark_for_add 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_mark_for_add needs a policy

This tool modifies source control staging state rather than directly creating/deleting files. It prepares files for commit but does not irreversibly change data. The operation is reversible (files can be unmarked or commits can be reverted). Classified as Write rather than Execute because it performs a specific administrative action on version control rather than arbitrary command execution.

From the tool's definition Tool name 'sc_mark_for_add' and description 'Mark new file(s) for add in source control' indicate the tool stages/marks files for addition to version control, which is a reversible data modification operation.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

sc_mark_for_add Rate-limited

sc_mark_for_add 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_mark_for_add": {
      "limits": [
        {
          "counter": "sc_mark_for_add_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_mark_for_add

What does the sc_mark_for_add tool do? +

Mark new file(s) for add in 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_mark_for_add? +

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

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

Can I rate-limit sc_mark_for_add? +

Yes. Add a rate_limit block to the sc_mark_for_add 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_mark_for_add completely? +

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

sc_mark_for_add 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.