tab_prev · It2 MCP: Risk & Policy

WHAT IT DOES

What tab_prev does on It2mcp

AI agents invoke tab_prev 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 tab_prev needs a policy

This tool triggers a UI/navigation action in iTerm2 (switching tabs), which is an external operation affecting the terminal application state. It doesn't read data, write/create data, or destroy anything, but it does execute a control action on an external application. Severity is low since it only changes focus/navigation with no data impact.

From the tool's definition Switch to the previous tab in the current window

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

tab_prev Rate-limited

tab_prev 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": {
    "tab_prev": {
      "limits": [
        {
          "counter": "tab_prev_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 tab_prev

What does the tab_prev tool do? +

Switch to the previous tab in the current window. 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 tab_prev? +

Register the It2 MCP server in PolicyLayer and add a rule for tab_prev: 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 tab_prev? +

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

Can I rate-limit tab_prev? +

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

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

tab_prev 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.