diff --git a/cts/__init__.py b/cts/__init__.py
index feff2bbd39..0cafb8c8c9 100644
--- a/cts/__init__.py
+++ b/cts/__init__.py
@@ -1,2 +1,19 @@
-# This file is required for python packages.
-# It is intentionally empty.
+"""Python modules for Pacemaker's Cluster Test Suite (CTS)
+
+This package provides the following modules:
+
+CIB
+cib_xml
+CM_ais
+CM_lha
+CTSaudits
+CTS
+CTSscenarios
+CTStests
+CTSvars
+environment
+logging
+patterns
+remote
+watcher
+"""