multi_device · Phantom MCP: Risk & Policy

WHAT IT DOES

What multi_device does on Phantom

AI agents invoke multi_device to trigger actions in Phantom. 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 multi_device needs a policy

This tool executes test automation commands across multiple devices in parallel. While the primary purpose is benign testing, the ability to execute arbitrary actions on multiple devices simultaneously presents a high risk if an AI agent misuses it—it could launch apps, interact with UI elements, or trigger other sibling tools (like deep_link, launch_app, kill_app) across many devices at once, amplifying the blast…

From the tool's definition The tool performs automated actions across multiple devices simultaneously ('Execute la meme action sur plusieurs devices').

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

multi_device Rate-limited

multi_device 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": {
    "multi_device": {
      "limits": [
        {
          "counter": "multi_device_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 Phantom, so you can run agents against it safely.

FAQ

Questions about multi_device

What does the multi_device tool do? +

Execute la meme action sur plusieurs devices et retourne les resultats combines. Utile pour tester sur iOS + Android en une seule commande. It is categorised as a Execute tool in the Phantom MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on multi_device? +

Register the Phantom MCP server in PolicyLayer and add a rule for multi_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 Phantom. Nothing to install.

What risk level is multi_device? +

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

Can I rate-limit multi_device? +

Yes. Add a rate_limit block to the multi_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 multi_device completely? +

Set action: deny in the PolicyLayer policy for multi_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 multi_device? +

multi_device is provided by the Phantom MCP server (nthimpulse/phantom-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.