stop_session_timer · Rize MCP: Risk & Policy

WHAT IT DOES

What stop_session_timer does on Rize

AI agents invoke stop_session_timer to trigger actions in Rize. 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_timer needs a policy

This tool executes an action that changes the state of an external system (Rize time tracking). While it is not destructive (the session is not deleted), and not a simple read operation, it actively triggers a real-world consequence by terminating a timing operation.

From the tool's definition Tool name: 'stop_session_timer'; description: 'Stop the current session timer'. The tool triggers an external operation (stopping an active timer) whose effect depends on the current state of the system.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

stop_session_timer Rate-limited

stop_session_timer 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_timer": {
      "limits": [
        {
          "counter": "stop_session_timer_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 Rize, so you can run agents against it safely.

FAQ

Questions about stop_session_timer

What does the stop_session_timer tool do? +

Stop the current session timer. It is categorised as a Execute tool in the Rize 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_timer? +

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

What risk level is stop_session_timer? +

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

Can I rate-limit stop_session_timer? +

Yes. Add a rate_limit block to the stop_session_timer 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_timer completely? +

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

stop_session_timer is provided by the Rize MCP server (rize-io/mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.