diff --git a/lib/dotcom_web/controllers/tracker_controller.ex b/lib/dotcom_web/controllers/tracker_controller.ex
index c688c55972..b80b9b3aab 100644
--- a/lib/dotcom_web/controllers/tracker_controller.ex
+++ b/lib/dotcom_web/controllers/tracker_controller.ex
@@ -1,4 +1,9 @@
 defmodule DotcomWeb.TrackerController do
+  @moduledoc """
+  Along with tracker.js, this controller logs the path and session_id of the user.
+  It allows us to see what pages are being visited in a session.
+  """
+
   use DotcomWeb, :controller
 
   require Logger