wait_for_output · Persistent Terminal MCP Server MCP

WHAT IT DOES

What wait_for_output does on Persistent Terminal MCP Server

AI agents invoke wait_for_output to trigger actions in Persistent Terminal 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 wait_for_output needs a policy

This tool does not retrieve data in a read-only sense; rather, it synchronizes with the execution state of a running terminal session. Combined with write_terminal (which sends commands) and the server's core function of executing persistent terminal commands, wait_for_output is an integral part of command execution workflow.

From the tool's definition Tool operates on persistent terminal sessions that 'continue running even after disconnection' and waits for output to stabilize after commands are executed.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

wait_for_output Rate-limited

wait_for_output 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": {
    "wait_for_output": {
      "limits": [
        {
          "counter": "wait_for_output_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 Persistent Terminal MCP Server, so you can run agents against it safely.

FAQ

Questions about wait_for_output

What does the wait_for_output tool do? +

Wait for terminal output to stabilize. Useful after running commands to ensure all output is captured. It is categorised as a Execute tool in the Persistent Terminal 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 wait_for_output? +

Register the Persistent Terminal MCP Server MCP server in PolicyLayer and add a rule for wait_for_output: 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 Persistent Terminal MCP Server. Nothing to install.

What risk level is wait_for_output? +

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

Can I rate-limit wait_for_output? +

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

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

wait_for_output is provided by the Persistent Terminal MCP Server MCP server (masx200/persistent-terminal-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.