show_toast · Android MCP Server MCP: Risk & Policy

WHAT IT DOES

What show_toast does on Android MCP Server

AI agents invoke show_toast to trigger actions in Android MCP Server. 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 show_toast needs a policy

Showing a toast message triggers an action on the Android device (an external operation), placing it in the Execute category. The blast radius is low since toast messages are transient, non-persistent UI notifications with no data modification or destructive effects.

From the tool's definition 'Show a toast message' — triggers an external operation on the Android device via Termux, displaying a system-level toast notification

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

show_toast Rate-limited

show_toast 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": {
    "show_toast": {
      "limits": [
        {
          "counter": "show_toast_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 Android MCP Server, so you can run agents against it safely.

FAQ

Questions about show_toast

What does the show_toast tool do? +

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

How do I enforce a policy on show_toast? +

Register the Android MCP Server MCP server in PolicyLayer and add a rule for show_toast: 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 Android MCP Server. Nothing to install.

What risk level is show_toast? +

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

Can I rate-limit show_toast? +

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

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

show_toast is provided by the Android MCP Server MCP server (wujie272/android-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.