create_script · MCP For Unity MCP: Risk & Policy

WHAT IT DOES

What create_script does on MCP For Unity

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

WHY IT NEEDS A POLICY

Why create_script needs a policy

This tool creates a new file (C# script) in the Unity project, which is a Write operation. However, it carries high severity because arbitrary C# code written to the project can be compiled and executed by the Unity Editor, potentially enabling indirect code execution. The creation itself is reversible (file can be deleted), so Write is the primary category, but misuse could introduce malicious code into the project.

From the tool's definition Creates a new C# script in Assets/Scripts/Generated

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

create_script Rate-limited

create_script 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_script": {
      "limits": [
        {
          "counter": "create_script_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 MCP For Unity, so you can run agents against it safely.

FAQ

Questions about create_script

What does the create_script tool do? +

Creates a new C# script in Assets/Scripts/Generated. It is categorised as a Write tool in the MCP For Unity 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_script? +

Register the MCP For Unity MCP server in PolicyLayer and add a rule for create_script: 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 MCP For Unity. Nothing to install.

What risk level is create_script? +

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

Can I rate-limit create_script? +

Yes. Add a rate_limit block to the create_script 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_script completely? +

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

create_script is provided by the MCP For Unity MCP server (yunuscan/mcpforunity). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.