publish_plugin_event · HC3 MCP Server MCP: Risk & Policy

WHAT IT DOES

What publish_plugin_event does on HC3 MCP Server

AI agents invoke publish_plugin_event to trigger actions in HC3 MCP Server. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call — builds kicked off, notifications sent, workflows started.

WHY IT NEEDS A POLICY

Why publish_plugin_event needs a policy

Publishing events triggers external operations within the smart home system — other devices, scenes, or automations may react to these events. This is an Execute-category action because it causes side effects that depend on the event type/arguments, not merely reading or writing data.

From the tool's definition Publish various types of events through the plugin system

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

publish_plugin_event Rate-limited

publish_plugin_event stays usable, but rate-capped — a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "publish_plugin_event": {
      "limits": [
        {
          "counter": "publish_plugin_event_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

RATE-LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches HC3 MCP Server, so you can run agents against it safely.

FAQ

Questions about publish_plugin_event

What does the publish_plugin_event tool do? +

Publish various types of events through the plugin system. It is categorised as a Execute tool in the HC3 MCP Server MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on publish_plugin_event? +

Register the HC3 MCP Server MCP server in PolicyLayer and add a rule for publish_plugin_event: 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 HC3 MCP Server. Nothing to install.

What risk level is publish_plugin_event? +

publish_plugin_event is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.

Can I rate-limit publish_plugin_event? +

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

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

publish_plugin_event is provided by the HC3 MCP Server MCP server (jangabrielsson/hc3_mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.