enviar_mensaje_moodle · Moodle MCP: Risk & Policy

WHAT IT DOES

What enviar_mensaje_moodle does on Moodle

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

WHY IT NEEDS A POLICY

Why enviar_mensaje_moodle needs a policy

This tool creates and stores new message records in Moodle, making it a Write operation. It modifies system state by adding messages to user inboxes. Severity is medium because while messages can be sent to many users, they are not destructive (can be deleted), not financial, and do not execute arbitrary code.

From the tool's definition Tool sends private messages to one or more users (max 50 recipients per call) via Moodle's core_message_send_instant_messages API. The description explicitly states 'Send a private Moodle message', which creates new message data in the Moodle system.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

enviar_mensaje_moodle Rate-limited

enviar_mensaje_moodle 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": {
    "enviar_mensaje_moodle": {
      "limits": [
        {
          "counter": "enviar_mensaje_moodle_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 Moodle, so you can run agents against it safely.

FAQ

Questions about enviar_mensaje_moodle

What does the enviar_mensaje_moodle tool do? +

Send a private Moodle message to one or more user ids. Max 50 recipients per call. Uses core_message_send_instant_messages. It is categorised as a Write tool in the Moodle MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on enviar_mensaje_moodle? +

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

What risk level is enviar_mensaje_moodle? +

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

Can I rate-limit enviar_mensaje_moodle? +

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

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

enviar_mensaje_moodle is provided by the Moodle MCP server (marcosnahuel/moodle-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.