press_keyboard_key · Macinput MCP: Risk & Policy

WHAT IT DOES

What press_keyboard_key does on Macinput

AI agents invoke press_keyboard_key to trigger actions in Macinput. 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 press_keyboard_key needs a policy

Pressing keyboard keys with modifiers (e.g., Cmd+Q, Cmd+Delete, Ctrl+Alt+Del) can trigger arbitrary system actions, launch/close applications, delete files, or execute commands. This is an Execute-category tool because it drives external system operations whose effects depend on which keys are pressed.

From the tool's definition 'Press and release a key with optional modifiers' on a macOS desktop GUI automation server that 'enables AI agents to control the desktop GUI through keyboard input'

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

press_keyboard_key Rate-limited

press_keyboard_key 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": {
    "press_keyboard_key": {
      "limits": [
        {
          "counter": "press_keyboard_key_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 Macinput, so you can run agents against it safely.

FAQ

Questions about press_keyboard_key

What does the press_keyboard_key tool do? +

Press and release a key with optional modifiers. It is categorised as a Execute tool in the Macinput MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on press_keyboard_key? +

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

What risk level is press_keyboard_key? +

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

Can I rate-limit press_keyboard_key? +

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

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

press_keyboard_key is provided by the Macinput MCP server (sigma711/macinput). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.