simctl_create_device · Simctl MCP: Risk & Policy

WHAT IT DOES

What simctl_create_device does on Simctl

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

WHY IT NEEDS A POLICY

Why simctl_create_device needs a policy

This tool creates a new simulator device, which is a reversible operation—the device can be deleted later (as evidenced by the sibling tool 'simctl_delete_device'). It modifies the simulator environment by adding a new device but does not execute arbitrary code, delete data irreversibly, or move money.

From the tool's definition Tool name 'simctl_create_device' and description 'Create a new simulator device' indicate the tool creates a new resource (a simulator device).

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

simctl_create_device Rate-limited

simctl_create_device 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": {
    "simctl_create_device": {
      "limits": [
        {
          "counter": "simctl_create_device_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 Simctl, so you can run agents against it safely.

FAQ

Questions about simctl_create_device

What does the simctl_create_device tool do? +

Create a new simulator device. It is categorised as a Write tool in the Simctl MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on simctl_create_device? +

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

What risk level is simctl_create_device? +

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

Can I rate-limit simctl_create_device? +

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

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

simctl_create_device is provided by the Simctl MCP server (nzrsky/simctl-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.