schedule_message · Bluebubbles MCP: Risk & Policy

WHAT IT DOES

What schedule_message does on Bluebubbles

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

WHY IT NEEDS A POLICY

Why schedule_message needs a policy

This tool creates a scheduled message entry that will be sent in the future. It is reversible (the sibling tool 'delete_scheduled_message' exists, implying cancellation is possible), so it falls under Write rather than Execute. Misuse could lead to unwanted messages being sent, but the blast radius is moderate.

From the tool's definition Schedule a message to be sent at a future time

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

schedule_message Rate-limited

schedule_message 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": {
    "schedule_message": {
      "limits": [
        {
          "counter": "schedule_message_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 Bluebubbles, so you can run agents against it safely.

FAQ

Questions about schedule_message

What does the schedule_message tool do? +

Schedule a message to be sent at a future time. It is categorised as a Write tool in the Bluebubbles MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on schedule_message? +

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

What risk level is schedule_message? +

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

Can I rate-limit schedule_message? +

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

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

schedule_message is provided by the Bluebubbles MCP server (metaember/bluebubbles-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.