browser_keyboard_down · MCProxy MCP: Risk & Policy

WHAT IT DOES

What browser_keyboard_down does on MCProxy

AI agents invoke browser_keyboard_down to trigger actions in MCProxy. 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 browser_keyboard_down needs a policy

This tool triggers browser keyboard input actions, which are external operations that interact with a live headless browser session. Keyboard actions can be used to trigger UI behaviors, submit forms, or perform complex key combinations — making this an Execute-category tool.

From the tool's definition Hold down a key (for modifier keys or key combinations). Remember to release with keyboard_up.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

browser_keyboard_down Rate-limited

browser_keyboard_down 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": {
    "browser_keyboard_down": {
      "limits": [
        {
          "counter": "browser_keyboard_down_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 MCProxy, so you can run agents against it safely.

FAQ

Questions about browser_keyboard_down

What does the browser_keyboard_down tool do? +

Hold down a key (for modifier keys or key combinations). Remember to release with keyboard_up. It is categorised as a Execute tool in the MCProxy MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on browser_keyboard_down? +

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

What risk level is browser_keyboard_down? +

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

Can I rate-limit browser_keyboard_down? +

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

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

browser_keyboard_down is provided by the MCProxy MCP server (saladtechnologies/mcproxy). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.