create_window · TmuxControlLib MCP Server MCP: Risk & Policy

WHAT IT DOES

What create_window does on TmuxControlLib MCP Server

AI agents use create_window to create or update resources in TmuxControlLib MCP Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your TmuxControlLib MCP Server environment.

WHY IT NEEDS A POLICY

Why create_window needs a policy

Creating a new tmux window is a reversible write operation — it instantiates a new resource within an existing session. It does not execute arbitrary commands on its own, though it does set up an environment where commands could later be run. The blast radius is moderate since misuse could clutter or disrupt session organization, but the action itself is reversible (windows can be killed).

From the tool's definition "Create a new window in a session"

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

create_window Rate-limited

create_window stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "create_window": {
      "limits": [
        {
          "counter": "create_window_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches TmuxControlLib MCP Server, so you can run agents against it safely.

FAQ

Questions about create_window

What does the create_window tool do? +

Create a new window in a session. It is categorised as a Write tool in the TmuxControlLib MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on create_window? +

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

What risk level is create_window? +

create_window is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit create_window? +

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

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

create_window is provided by the TmuxControlLib MCP Server MCP server (jbwinters/tmuxcontrollib). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.