key_combination · Mac MCP: Risk & Policy

WHAT IT DOES

What key_combination does on Mac

AI agents invoke key_combination to trigger actions in Mac. 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 key_combination needs a policy

Simulates keyboard input by pressing key combinations with modifiers in the focused application. This can trigger arbitrary application actions (save, delete, quit, copy, paste, etc.) depending on arguments, making it an Execute-class tool. Misuse could trigger destructive or sensitive operations within any app, warranting high severity.

From the tool's definition Presses a focused-app or menu key combination with modifiers

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

key_combination Rate-limited

key_combination 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": {
    "key_combination": {
      "limits": [
        {
          "counter": "key_combination_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 Mac, so you can run agents against it safely.

FAQ

Questions about key_combination

What does the key_combination tool do? +

Presses a focused-app or menu key combination with modifiers; OS-global hotkeys such as Electron globalShortcut are not guaranteed. It is categorised as a Execute tool in the Mac MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on key_combination? +

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

What risk level is key_combination? +

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

Can I rate-limit key_combination? +

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

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

key_combination is provided by the Mac MCP server (laststance/mac-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.