execute_luau · Melo MCP: Risk & Policy

WHAT IT DOES

What execute_luau does on Melo

AI agents invoke execute_luau to trigger actions in Melo. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call — builds kicked off, notifications sent, workflows started.

WHY IT NEEDS A POLICY

Why execute_luau needs a policy

This tool allows execution of arbitrary code in the Roblox Studio environment. An AI agent with access to this could execute malicious scripts, manipulate game objects, exfiltrate data from projects, corrupt game logic, or cause widespread damage within Studio. The 'arbitrary' qualifier means there are no restrictions on what code can be run.

From the tool's definition Tool description explicitly states 'Run arbitrary Luau code directly in Studio'. The name 'execute_luau' combined with 'arbitrary code' clearly indicates dynamic code execution capability.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

execute_luau Rate-limited

execute_luau stays usable, but rate-capped — a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "execute_luau": {
      "limits": [
        {
          "counter": "execute_luau_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

RATE-LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches Melo, so you can run agents against it safely.

FAQ

Questions about execute_luau

What does the execute_luau tool do? +

Run arbitrary Luau code directly in Studio. It is categorised as a Execute tool in the Melo MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on execute_luau? +

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

What risk level is execute_luau? +

execute_luau is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.

Can I rate-limit execute_luau? +

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

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

execute_luau is provided by the Melo MCP server (yannyhl/linkedsword-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.