update_user_referrer · Fuul MCP Server MCP: Risk & Policy

WHAT IT DOES

What update_user_referrer does on Fuul MCP Server

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

WHY IT NEEDS A POLICY

Why update_user_referrer needs a policy

The tool modifies user referrer records reversibly (characteristic of Write category). While the description is empty, the name and server context (affiliate program management with financial incentives) indicate data mutation.

From the tool's definition Tool name 'update_user_referrer' indicates modification of user referrer data. Sibling tools include create/delete operations on incentives and triggers, suggesting this server manages mutable affiliate program state.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

update_user_referrer Rate-limited

update_user_referrer 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": {
    "update_user_referrer": {
      "limits": [
        {
          "counter": "update_user_referrer_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 Fuul MCP Server, so you can run agents against it safely.

FAQ

Questions about update_user_referrer

What does the update_user_referrer tool do? +

update_user_referrer. It is categorised as a Write tool in the Fuul MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on update_user_referrer? +

Register the Fuul MCP Server MCP server in PolicyLayer and add a rule for update_user_referrer: 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 Fuul MCP Server. Nothing to install.

What risk level is update_user_referrer? +

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

Can I rate-limit update_user_referrer? +

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

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

update_user_referrer is provided by the Fuul MCP Server MCP server (kuyen-labs/mcp_server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.