os_click · OScribe MCP: Risk & Policy

WHAT IT DOES

What os_click does on OScribe

AI agents invoke os_click to trigger actions in OScribe. 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 os_click needs a policy

Clicking UI elements can trigger arbitrary application actions (opening files, submitting forms, deleting data, launching programs, confirming dialogs). The blast radius is high because the exact effect depends on what is under the cursor at the time, and in the context of a vision-based desktop automation server it could interact with any application on the system.

From the tool's definition 'Click at current cursor position' — triggers a UI click action on whatever element is under the cursor, driving desktop automation via simulated user input

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

os_click Rate-limited

os_click 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": {
    "os_click": {
      "limits": [
        {
          "counter": "os_click_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 OScribe, so you can run agents against it safely.

FAQ

Questions about os_click

What does the os_click tool do? +

Click at current cursor position. Use os_move first to position the cursor, then os_click to click. This ensures precise clicking by separating movement and click. It is categorised as a Execute tool in the OScribe MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on os_click? +

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

What risk level is os_click? +

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

Can I rate-limit os_click? +

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

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

os_click is provided by the OScribe MCP server (mikealkeal/oscribe). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.