act · Windows Computer Use MCP: Risk & Policy

WHAT IT DOES

What act does on Windows Computer Use

AI agents invoke act to trigger actions in Windows Computer Use. 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 act needs a policy

Given the server's purpose of full Windows desktop control with low-level input injection and the tool name 'act' (implying performing an action), this tool almost certainly executes desktop actions such as mouse clicks, keyboard input, or other UI interactions.

From the tool's definition Tool name 'act' on a server described as enabling 'full control of a Windows desktop with native screen capture, low-level input injection, game-grade input' — sibling tools include 'play', 'process', 'record', 'screenshot', 'system', 'window', suggesting…

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

act Rate-limited

act 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": {
    "act": {
      "limits": [
        {
          "counter": "act_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 Windows Computer Use, so you can run agents against it safely.

FAQ

Questions about act

What does the act tool do? +

act. It is categorised as a Execute tool in the Windows Computer Use MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on act? +

Register the Windows Computer Use MCP server in PolicyLayer and add a rule for act: 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 Windows Computer Use. Nothing to install.

What risk level is act? +

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

Can I rate-limit act? +

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

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

act is provided by the Windows Computer Use MCP server (sshh12/windows-computer-use-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

// THE FULL RECORD

act is one line of Windows Computer Use's registry record.

The record carries the whole server: verified identity, auth posture, risk grade, every tool classified, recommended policy — re-checked continuously.

Teams ship this data inside their own products. See what a licence covers →