manage_subscribers · Kit MCP: Risk & Policy

WHAT IT DOES

What manage_subscribers does on Kit

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

WHY IT NEEDS A POLICY

Why manage_subscribers needs a policy

This tool modifies subscriber data reversibly (subscribers can be added, updated, or re-added). While it creates or alters data, it does not irreversibly delete records (which would be Destructive) nor does it execute arbitrary code (Execute). The blast radius is high because bulk modifications to subscriber lists could disrupt marketing campaigns, trigger unintended communications, or alter customer segmentation.

From the tool's definition Tool name 'manage_subscribers' and description indicates it 'Manage Kit subscribers,' which encompasses creation, modification, and administration of subscriber records.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

manage_subscribers Rate-limited

manage_subscribers 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": {
    "manage_subscribers": {
      "limits": [
        {
          "counter": "manage_subscribers_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 Kit, so you can run agents against it safely.

FAQ

Questions about manage_subscribers

What does the manage_subscribers tool do? +

Manage Kit subscribers. To find most engaged subscribers, use. It is categorised as a Write tool in the Kit MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on manage_subscribers? +

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

What risk level is manage_subscribers? +

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

Can I rate-limit manage_subscribers? +

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

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

manage_subscribers is provided by the Kit MCP server (@dancumberland/kit-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.