switch_app · Mcp Desktop MCP: Risk & Policy

WHAT IT DOES

What switch_app does on Mcp Desktop

AI agents invoke switch_app to trigger actions in Mcp Desktop. 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 switch_app needs a policy

This tool triggers an external OS-level operation (activating/focusing an application window) rather than simply reading data or writing/modifying content. It causes a side effect on the desktop environment. The blast radius is low since it only changes window focus, but it is an action with real system effects, placing it in the Execute category.

From the tool's definition Bring an application to the foreground

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

switch_app Rate-limited

switch_app 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": {
    "switch_app": {
      "limits": [
        {
          "counter": "switch_app_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 Mcp Desktop, so you can run agents against it safely.

FAQ

Questions about switch_app

What does the switch_app tool do? +

Bring an application to the foreground. It is categorised as a Execute tool in the Mcp Desktop MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on switch_app? +

Register the Mcp Desktop MCP server in PolicyLayer and add a rule for switch_app: 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 Mcp Desktop. Nothing to install.

What risk level is switch_app? +

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

Can I rate-limit switch_app? +

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

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

switch_app is provided by the Mcp Desktop MCP server (mocha06/mcp-desktop). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.