split_pane · TmuxControlLib MCP Server MCP: Risk & Policy

WHAT IT DOES

What split_pane does on TmuxControlLib MCP Server

AI agents invoke split_pane to trigger actions in TmuxControlLib 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 split_pane needs a policy

Splitting a pane is an external operation that modifies the tmux session layout by creating a new terminal pane. This is an Execute-level action as it triggers an external operation (tmux split-window), though it does not run arbitrary code itself. Severity is medium because misuse could disrupt terminal layout or expose new pane contexts, but impact is generally recoverable.

From the tool's definition 'Split a pane to create a new pane' — creates a new tmux pane by splitting an existing one, triggering an external terminal operation

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

split_pane Rate-limited

split_pane 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": {
    "split_pane": {
      "limits": [
        {
          "counter": "split_pane_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 TmuxControlLib MCP Server, so you can run agents against it safely.

FAQ

Questions about split_pane

What does the split_pane tool do? +

Split a pane to create a new pane. It is categorised as a Execute tool in the TmuxControlLib 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 split_pane? +

Register the TmuxControlLib MCP Server MCP server in PolicyLayer and add a rule for split_pane: 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 split_pane? +

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

Can I rate-limit split_pane? +

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

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

split_pane 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.