load_rom · MCP PyBoy Emulator Server MCP: Risk & Policy

WHAT IT DOES

What load_rom does on MCP PyBoy Emulator Server

AI agents invoke load_rom to trigger actions in MCP PyBoy Emulator Server. 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 load_rom needs a policy

Loading a ROM initiates emulation execution — it triggers an external operation (starting a game emulation session) rather than simply reading or writing data. The description is empty, so confidence is reduced, but the server description explicitly lists 'load ROMs' as a capability, and loading a ROM causes the emulator to begin executing game code.

From the tool's definition Tool name 'load_rom' on a PyBoy emulator server that provides capabilities to 'load ROMs' and 'control games'

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

load_rom Rate-limited

load_rom 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": {
    "load_rom": {
      "limits": [
        {
          "counter": "load_rom_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 MCP PyBoy Emulator Server, so you can run agents against it safely.

FAQ

Questions about load_rom

What does the load_rom tool do? +

load_rom. It is categorised as a Execute tool in the MCP PyBoy Emulator Server MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on load_rom? +

Register the MCP PyBoy Emulator Server MCP server in PolicyLayer and add a rule for load_rom: 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 MCP PyBoy Emulator Server. Nothing to install.

What risk level is load_rom? +

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

Can I rate-limit load_rom? +

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

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

load_rom is provided by the MCP PyBoy Emulator Server MCP server (ssimonitch/mcp-pyboy). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.