save_scene · Unity MCP: Risk & Policy

WHAT IT DOES

What save_scene does on Unity MCP

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

WHY IT NEEDS A POLICY

Why save_scene needs a policy

This tool modifies scene files on disk, which is reversible through undo/version control systems. It does not delete data (Destructive), execute arbitrary code (Execute), move money (Financial), or merely read data (Read). The severity is medium because while scene modifications can affect project integrity, they are recoverable and don't have catastrophic real-world impact like financial or security breaches.

From the tool's definition Tool name 'save_scene' and description 'Save the current scene or all open scenes' indicates creation or modification of persistent data (scene files).

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

save_scene Rate-limited

save_scene 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": {
    "save_scene": {
      "limits": [
        {
          "counter": "save_scene_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 Unity MCP, so you can run agents against it safely.

FAQ

Questions about save_scene

What does the save_scene tool do? +

Save the current scene or all open scenes. Essential for preserving changes made during automation. It is categorised as a Write tool in the Unity MCP MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on save_scene? +

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

What risk level is save_scene? +

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

Can I rate-limit save_scene? +

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

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

save_scene is provided by the Unity MCP server (muammar-yacoob/unity-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.