create_plugin · Sage MCP Server MCP: Risk & Policy

WHAT IT DOES

What create_plugin does on Sage MCP Server

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

WHY IT NEEDS A POLICY

Why create_plugin needs a policy

Creating a new plugin is a write operation that introduces new code/configuration into the Sage testbed environment. While reversible (plugins can be deleted), it has moderate blast radius if an AI agent creates malicious or resource-intensive plugins that could interfere with the testbed.

From the tool's definition Tool name 'create_plugin' and description 'Create a new Sage plugin from description' indicate creation of new software artifacts in the Sage system. This is a reversible write operation that modifies the plugin repository state.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

create_plugin Rate-limited

create_plugin 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": {
    "create_plugin": {
      "limits": [
        {
          "counter": "create_plugin_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 Sage MCP Server, so you can run agents against it safely.

FAQ

Questions about create_plugin

What does the create_plugin tool do? +

Create a new Sage plugin from description. It is categorised as a Write tool in the Sage 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 create_plugin? +

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

What risk level is create_plugin? +

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

Can I rate-limit create_plugin? +

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

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

create_plugin is provided by the Sage MCP Server MCP server (waggle-sensor/sage-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.