type_text · Linux Computer Use MCP: Risk & Policy

WHAT IT DOES

What type_text does on Linux Computer Use

AI agents invoke type_text to trigger actions in Linux 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 type_text needs a policy

Typing text into an active application constitutes an external operation with real side effects: it can submit forms, execute terminal commands, modify documents, or trigger UI actions. The blast radius is high because the target application is unknown and malicious input could execute shell commands or exfiltrate data.

From the tool's definition 'Type literal text at the current cursor' on a Linux/X11 desktop controlled via xdotool/AT-SPI — triggers keyboard input events in whatever application has focus

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

type_text Rate-limited

type_text 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": {
    "type_text": {
      "limits": [
        {
          "counter": "type_text_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 Linux Computer Use, so you can run agents against it safely.

FAQ

Questions about type_text

What does the type_text tool do? +

Type literal text at the current cursor. It is categorised as a Execute tool in the Linux 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 type_text? +

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

What risk level is type_text? +

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

Can I rate-limit type_text? +

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

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

type_text is provided by the Linux Computer Use MCP server (tak-uukti/linux-computer-use). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.