stop_session · gdb and rr Debugging MCP: Risk & Policy

WHAT IT DOES

What stop_session does on gdb and rr Debugging

AI agents invoke stop_session to trigger actions in gdb and rr Debugging. 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 stop_session needs a policy

While stopping a debugging session is not irreversible in the destructive sense (you can restart), it is an Execute action because it triggers termination of an external process. The severity is high because a malicious agent could use this to abruptly halt debugging of security-critical code, disrupt analysis workflows, or interfere with legitimate debugging tasks.

From the tool's definition Kills the GDB process via 'stop_session' — terminates an active debugging session and cleans up resources. This is an external operation with side effects that cannot be trivially undone without restarting the session.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

stop_session Rate-limited

stop_session 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": {
    "stop_session": {
      "limits": [
        {
          "counter": "stop_session_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 gdb and rr Debugging, so you can run agents against it safely.

FAQ

Questions about stop_session

What does the stop_session tool do? +

Stop and clean up a GDB session (kills the GDB process). It is categorised as a Execute tool in the gdb and rr Debugging MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on stop_session? +

Register the gdb and rr Debugging MCP server in PolicyLayer and add a rule for stop_session: 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 gdb and rr Debugging. Nothing to install.

What risk level is stop_session? +

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

Can I rate-limit stop_session? +

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

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

stop_session is provided by the gdb and rr Debugging MCP server (schuay/gdb-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.