fill_region · Ice Puzzle MCP: Risk & Policy

WHAT IT DOES

What fill_region does on Ice Puzzle

AI agents use fill_region 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 fill_region needs a policy

This tool modifies level data by filling regions with tile types, which is a reversible write operation typical of level design tools. While it includes an auto-solve component (Execute-like), the primary action is creating/modifying game state rather than running arbitrary code.

From the tool's definition Tool description states 'Fill a rectangular region with a tile type', which is a creation/modification action.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

fill_region Rate-limited

fill_region 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": {
    "fill_region": {
      "limits": [
        {
          "counter": "fill_region_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 fill_region

What does the fill_region tool do? +

Fill a rectangular region with a tile type. Auto-solves. 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 fill_region? +

Register the Ice Puzzle MCP server in PolicyLayer and add a rule for fill_region: 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 fill_region? +

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

Can I rate-limit fill_region? +

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

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

fill_region 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.