set_barrier · Ice Puzzle MCP: Risk & Policy

WHAT IT DOES

What set_barrier does on Ice Puzzle

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

WHY IT NEEDS A POLICY

Why set_barrier needs a policy

This tool creates or modifies barrier objects within an Ice Puzzle level, changing the level's configuration. While it introduces hazards that affect gameplay, it is reversible (barriers can be adjusted, repositioned, or cleared using sibling tools like clear_level or clear_region). The 'kill' mechanic is a gameplay consequence, not a system-level destructive action.

From the tool's definition Tool description states 'Set barrier position' which modifies level state. The parenthetical '(kills if pressure plate not activated)' describes game mechanics that affect the level's behavior but does not indicate irreversible deletion—barriers can be…

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

set_barrier Rate-limited

set_barrier 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": {
    "set_barrier": {
      "limits": [
        {
          "counter": "set_barrier_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 Ice Puzzle, so you can run agents against it safely.

FAQ

Questions about set_barrier

What does the set_barrier tool do? +

Set barrier position (kills if pressure plate not activated). It is categorised as a Write tool in the Ice Puzzle MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on set_barrier? +

Register the Ice Puzzle MCP server in PolicyLayer and add a rule for set_barrier: 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 Ice Puzzle. Nothing to install.

What risk level is set_barrier? +

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

Can I rate-limit set_barrier? +

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

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

set_barrier is provided by the Ice Puzzle MCP server (wmoten/ice-puzzle-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.