hooks_session-start · Ruflo MCP: Risk & Policy

WHAT IT DOES

What hooks_session-start does on Ruflo

AI agents invoke hooks_session-start to trigger actions in Ruflo. 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 hooks_session-start needs a policy

This tool executes system-level operations (session initialization and daemon startup via Bash hooks). While not destructive by itself, it has significant blast radius if an AI agent misuses it—daemons could consume resources, interfere with system stability, or execute unintended background processes.

From the tool's definition Tool name 'hooks_session-start' combined with description referencing 'Initialize a new session and auto-start daemon' and 'native Bash hooks' indicates execution of shell/bash commands.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

hooks_session-start Rate-limited

hooks_session-start 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": {
    "hooks_session-start": {
      "limits": [
        {
          "counter": "hooks_session-start_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 Ruflo, so you can run agents against it safely.

FAQ

Questions about hooks_session-start

What does the hooks_session-start tool do? +

Initialize a new session and auto-start daemon Use when native Bash hooks (via Claude Code\. It is categorised as a Execute tool in the Ruflo MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on hooks_session-start? +

Register the Ruflo MCP server in PolicyLayer and add a rule for hooks_session-start: 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 Ruflo. Nothing to install.

What risk level is hooks_session-start? +

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

Can I rate-limit hooks_session-start? +

Yes. Add a rate_limit block to the hooks_session-start 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 hooks_session-start completely? +

Set action: deny in the PolicyLayer policy for hooks_session-start. 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 hooks_session-start? +

hooks_session-start is provided by the Ruflo MCP server (ruvnet/ruflo). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.