tmux_split_window · Tmux MCP: Risk & Policy

WHAT IT DOES

What tmux_split_window does on Tmux

AI agents invoke tmux_split_window to trigger actions in Tmux. 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 tmux_split_window needs a policy

Based on the tool name and server context, tmux_split_window likely splits a tmux window into panes, which is an Execute-level action as it triggers external terminal operations. The description is empty, lowering confidence, but the sibling tools (remote_bash_execute, tmux_create_session, etc.) indicate this server executes shell/terminal commands. Splitting a window could also enable command execution in new panes.

From the tool's definition Tool name 'tmux_split_window' on a server that 'Allows AI assistants to create, manage, and interact with tmux sessions, windows, and panes programmatically.'

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

tmux_split_window Rate-limited

tmux_split_window 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": {
    "tmux_split_window": {
      "limits": [
        {
          "counter": "tmux_split_window_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 Tmux, so you can run agents against it safely.

FAQ

Questions about tmux_split_window

What does the tmux_split_window tool do? +

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

How do I enforce a policy on tmux_split_window? +

Register the Tmux MCP server in PolicyLayer and add a rule for tmux_split_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 Tmux. Nothing to install.

What risk level is tmux_split_window? +

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

Can I rate-limit tmux_split_window? +

Yes. Add a rate_limit block to the tmux_split_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 tmux_split_window completely? +

Set action: deny in the PolicyLayer policy for tmux_split_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 tmux_split_window? +

tmux_split_window is provided by the Tmux MCP server (wenlixiao-cs/tmux-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.