place_prop · ChatRPG MCP: Risk & Policy

WHAT IT DOES

What place_prop does on ChatRPG

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

WHY IT NEEDS A POLICY

Why place_prop needs a policy

This tool creates or modifies battlefield props, which is a reversible change to game state. It does not execute arbitrary code, delete data permanently, move money, or retrieve information passively. 'Manage' suggests potential updates to existing props.

From the tool's definition The tool description states it can "Place or manage interactive props on the battlefield" — 'place' and 'manage' are write operations that create or modify game state objects (props) reversibly within the game world.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

place_prop Rate-limited

place_prop 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": {
    "place_prop": {
      "limits": [
        {
          "counter": "place_prop_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 ChatRPG, so you can run agents against it safely.

FAQ

Questions about place_prop

What does the place_prop tool do? +

Place or manage interactive props on the battlefield (barrels, doors, chests, etc.). It is categorised as a Write tool in the ChatRPG MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on place_prop? +

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

What risk level is place_prop? +

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

Can I rate-limit place_prop? +

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

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

place_prop is provided by the ChatRPG MCP server (mnehmos/mnehmos.chatrpg.game). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.