mqtt_disconnect · MQTT MCP Server MCP: Risk & Policy

WHAT IT DOES

What mqtt_disconnect does on MQTT MCP Server

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

WHY IT NEEDS A POLICY

Why mqtt_disconnect needs a policy

This tool performs a state modification (disconnecting) but is reversible—a new connection can be established. It does not delete data, execute arbitrary code, create financial obligations, or cause irreversible damage. It falls into Write category as a connection state management operation that modifies system state but can be undone.

From the tool's definition mqtt_disconnect function disconnects from an MQTT broker. The action modifies the connection state by closing an active connection, which is a reversible state change (the connection can be re-established with mqtt_connect).

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

mqtt_disconnect Rate-limited

mqtt_disconnect 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": {
    "mqtt_disconnect": {
      "limits": [
        {
          "counter": "mqtt_disconnect_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 MQTT MCP Server, so you can run agents against it safely.

FAQ

Questions about mqtt_disconnect

What does the mqtt_disconnect tool do? +

Disconnect from the MQTT broker. It is categorised as a Write tool in the MQTT 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 mqtt_disconnect? +

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

What risk level is mqtt_disconnect? +

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

Can I rate-limit mqtt_disconnect? +

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

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

mqtt_disconnect is provided by the MQTT MCP Server MCP server (sergiudanstan/mqtt-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.