create_tab · Terminally MCP: Risk & Policy

WHAT IT DOES

What create_tab does on Terminally MCP

AI agents invoke create_tab to trigger actions in Terminally MCP. 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 create_tab needs a policy

Creating a new tmux window/terminal session is an execution-environment operation — it spawns a new shell session that can subsequently run arbitrary commands. While creating the tab itself doesn't immediately execute user code, it sets up an execution context within a terminal control system.

From the tool's definition Create a new terminal tab (tmux window)

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

create_tab Rate-limited

create_tab 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": {
    "create_tab": {
      "limits": [
        {
          "counter": "create_tab_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 Terminally MCP, so you can run agents against it safely.

FAQ

Questions about create_tab

What does the create_tab tool do? +

Create a new terminal tab (tmux window). It is categorised as a Execute tool in the Terminally MCP MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on create_tab? +

Register the Terminally MCP server in PolicyLayer and add a rule for create_tab: 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 Terminally MCP. Nothing to install.

What risk level is create_tab? +

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

Can I rate-limit create_tab? +

Yes. Add a rate_limit block to the create_tab 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_tab completely? +

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

create_tab is provided by the Terminally MCP server (nighttrek/terminally-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

// THE FULL RECORD

create_tab is one line of Terminally's registry record.

The record carries the whole server: verified identity, auth posture, risk grade, every tool classified, recommended policy — re-checked continuously.

Teams ship this data inside their own products. See what a licence covers →