set_layer_property · QGIS MCP: Risk & Policy

WHAT IT DOES

What set_layer_property does on QGIS MCP

AI agents use set_layer_property 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 set_layer_property needs a policy

This tool creates or modifies data reversibly (changing opacity or renaming layers). While these changes affect the visual/organizational state of a QGIS project, they are not destructive (can be undone/reverted) and do not execute arbitrary code or trigger external side effects.

From the tool's definition Tool name 'set_layer_property' and description indicates it modifies layer properties including opacity and name. These are reversible modifications to GIS project state.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

set_layer_property Rate-limited

set_layer_property 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": {
    "set_layer_property": {
      "limits": [
        {
          "counter": "set_layer_property_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 set_layer_property

What does the set_layer_property tool do? +

Set a layer property. Supported properties: opacity (0.0-1.0), name (string),. 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 set_layer_property? +

Register the QGIS MCP server in PolicyLayer and add a rule for set_layer_property: 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 set_layer_property? +

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

Can I rate-limit set_layer_property? +

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

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

set_layer_property 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.