High Risk →

start_session

Create or replace a session. PURPOSE: - Initialize conversation state - Optionally store stable user profile fields DO: - pass stable or semi-stable profile information in user_profile - pass preferred_language if known - call this before other hotel-related tools DO NOT: - do NOT put city inside...

Part of the Waysway server.

start_session can trigger actions in Waysway, with no limits today. PolicyLayer puts allow, deny, and rate-limit rules on every call. Live in minutes.

SECURE WAYSWAY →

Free to start. No card required.

AI agents invoke start_session to trigger processes or run actions in Waysway. Execute operations can have side effects beyond the immediate call -- triggering builds, sending notifications, or starting workflows. Rate limits and argument validation are essential to prevent runaway execution.

start_session can trigger processes with real-world consequences. An uncontrolled agent might start dozens of builds, send mass notifications, or kick off expensive compute jobs. PolicyLayer enforces rate limits and validates arguments to keep execution within safe bounds.

Execute tools trigger processes. Rate-limit and validate arguments to prevent unintended side effects.

policy.json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "start_session": {
      "limits": [
        {
          "counter": "start_session_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

See the full Waysway policy for all 20 tools.

Get this rule live on your own Waysway server in minutes. PolicyLayer enforces it on every call, before it runs.

ENFORCE ON MY WAYSWAY →

View all 20 tools →

These attack patterns abuse exactly the kind of access start_session gives an agent. Each links to the full case and the policy that stops it:

Browse the full MCP Attack Database →

Every attack above starts with a tool call. PolicyLayer checks each one against your policy first, so start_session only ever does what you allow.

SECURE WAYSWAY →

Other execute tools across the catalogue. The same approach applies to each: rate-limit and validate the arguments.

What does the start_session tool do? +

Create or replace a session. PURPOSE: - Initialize conversation state - Optionally store stable user profile fields DO: - pass stable or semi-stable profile information in user_profile - pass preferred_language if known - call this before other hotel-related tools DO NOT: - do NOT put city inside user_profile - do NOT put checkin_date or checkout_date inside user_profile - do NOT put search filters inside user_profile CORRECT WORKFLOW: 1. start_session(...) 2. update_user_profile_from_model(...) # optional 3. update_stay_dates(...) # optional 4. search_hotels(city=..., ...) WRONG: user_profile = { "city": "New York", "checkin_date": "2023-04-01", "checkout_date": "2023-04-05" } RIGHT: start_session(user_profile={"preferred_language": "en"}) update_stay_dates(checkin_str="2023-04-01", checkout_str="2023-04-05") search_hotels(city="New York", ...). It is categorised as a Execute tool in the Waysway MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on start_session? +

Register the Waysway MCP server in PolicyLayer and add a rule for start_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 Waysway. Nothing to install.

What risk level is start_session? +

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

Can I rate-limit start_session? +

Yes. Add a rate_limit block to the start_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 start_session completely? +

Set action: deny in the PolicyLayer policy for start_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 start_session? +

start_session is provided by the Waysway MCP server (https://api.waysway.com/mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every Waysway tool call.

Deterministic rules across all 20 Waysway tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.

Free to start. No card required.

4,600+ MCP servers and 31,000+ tools scanned and risk-classified.

// GET IN TOUCH

Have a question or want to learn more? Send us a message.

Message sent.

We'll get back to you soon.