set_preferences · Luma Events MCP: Risk & Policy

WHAT IT DOES

What set_preferences does on Luma Events

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

WHY IT NEEDS A POLICY

Why set_preferences needs a policy

The tool name 'set_preferences' indicates it creates or modifies user preference data, consistent with the Write category. Without a description, we cannot determine if this affects only the current session or persistent state, hence medium-low severity and reduced confidence (0.6).

From the tool's definition Tool name 'set_preferences' combined with context that this server manages events and event preferences suggests the tool modifies user-stored settings. No description provided to confirm scope.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

set_preferences Rate-limited

set_preferences 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": {
    "set_preferences": {
      "limits": [
        {
          "counter": "set_preferences_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 Luma Events, so you can run agents against it safely.

FAQ

Questions about set_preferences

What does the set_preferences tool do? +

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

How do I enforce a policy on set_preferences? +

Register the Luma Events MCP server in PolicyLayer and add a rule for set_preferences: 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 Luma Events. Nothing to install.

What risk level is set_preferences? +

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

Can I rate-limit set_preferences? +

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

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

set_preferences is provided by the Luma Events MCP server (alx1p/luma-cal-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.