create_webhook_subscription · Smokeball MCP: Risk & Policy

WHAT IT DOES

What create_webhook_subscription does on Smokeball

AI agents use create_webhook_subscription to create or update resources in Smokeball — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Smokeball environment.

WHY IT NEEDS A POLICY

Why create_webhook_subscription needs a policy

This tool creates new data (a webhook subscription record) in a reversible manner—subscriptions can typically be deleted or modified later. It does not execute arbitrary code, delete data irreversibly, or move money.

From the tool's definition Tool creates a webhook subscription by registering an event listener with the Smokeball API. The description indicates it 'Create[s] a webhook subscription' with a required event_type parameter, establishing a new persistent configuration in the system.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

create_webhook_subscription Rate-limited

create_webhook_subscription stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "create_webhook_subscription": {
      "limits": [
        {
          "counter": "create_webhook_subscription_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches Smokeball, so you can run agents against it safely.

FAQ

Questions about create_webhook_subscription

What does the create_webhook_subscription tool do? +

Create a webhook subscription. event_type: from list_webhook_event_types. It is categorised as a Write tool in the Smokeball MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on create_webhook_subscription? +

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

What risk level is create_webhook_subscription? +

create_webhook_subscription is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit create_webhook_subscription? +

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

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

create_webhook_subscription is provided by the Smokeball MCP server (rosenadvertising/smokeball-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.