duplicate_layer · QGIS MCP: Risk & Policy

WHAT IT DOES

What duplicate_layer does on QGIS MCP

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

WHY IT NEEDS A POLICY

Why duplicate_layer needs a policy

This operation creates a new layer reversibly—the duplicate can be deleted, and the original remains unaffected. It does not execute arbitrary code, delete data irreversibly, or cause financial impact. The action is a standard Write operation within the GIS project context with minimal blast radius.

From the tool's definition Tool name 'duplicate_layer' and description 'Duplicate a layer (including its style) under a new name' indicate creation of a new layer resource through copying an existing one.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

duplicate_layer Rate-limited

duplicate_layer 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": {
    "duplicate_layer": {
      "limits": [
        {
          "counter": "duplicate_layer_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 QGIS MCP, so you can run agents against it safely.

FAQ

Questions about duplicate_layer

What does the duplicate_layer tool do? +

Duplicate a layer (including its style) under a new name. It is categorised as a Write tool in the QGIS MCP MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on duplicate_layer? +

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

What risk level is duplicate_layer? +

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

Can I rate-limit duplicate_layer? +

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

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

duplicate_layer is provided by the QGIS MCP server (nkarasiak/qgis-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.