update_room · Loenn MCP: Risk & Policy

WHAT IT DOES

What update_room does on Loenn

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

WHY IT NEEDS A POLICY

Why update_room needs a policy

The 'update_room' tool modifies existing room data in Celeste map files, which is a reversible write operation. While the description is empty, the tool name and server purpose (editing map files) clearly indicate this creates or modifies data. It's Write rather than Execute because it operates on specific game map structures, not arbitrary code execution.

From the tool's definition Tool name 'update_room' and server context enabling AI agents to 'edit' Celeste .bin map files. Sibling tools include 'add_room', 'add_entity', 'add_trigger' which are clearly write operations on game map data.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

update_room Rate-limited

update_room 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": {
    "update_room": {
      "limits": [
        {
          "counter": "update_room_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 Loenn, so you can run agents against it safely.

FAQ

Questions about update_room

What does the update_room tool do? +

update_room. It is categorised as a Write tool in the Loenn MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on update_room? +

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

What risk level is update_room? +

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

Can I rate-limit update_room? +

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

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

update_room is provided by the Loenn MCP server (magedeline/loenn-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.