session_split · It2 MCP: Risk & Policy

WHAT IT DOES

What session_split does on It2mcp

AI agents invoke session_split to trigger actions in It2mcp. 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 session_split needs a policy

Splitting a session creates a new terminal pane within iTerm2, which is an external operation that triggers UI/system changes. It doesn't just read data or write files, but executes a terminal control action. Misuse could result in proliferating unintended terminal sessions, though the blast radius is moderate since it doesn't directly run commands or delete data.

From the tool's definition Split an iTerm2 session into a new pane

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

session_split Rate-limited

session_split 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": {
    "session_split": {
      "limits": [
        {
          "counter": "session_split_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 It2mcp, so you can run agents against it safely.

FAQ

Questions about session_split

What does the session_split tool do? +

Split an iTerm2 session into a new pane. It is categorised as a Execute tool in the It2mcp MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on session_split? +

Register the It2 MCP server in PolicyLayer and add a rule for session_split: 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 It2mcp. Nothing to install.

What risk level is session_split? +

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

Can I rate-limit session_split? +

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

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

session_split is provided by the It2 MCP server (urjitbhatia/it2mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.