diff --git a/Modules/ExampleModule/include/ExampleSegTool2D.h b/Modules/ExampleModule/include/ExampleSegTool2D.h
index e69c355..7362c78 100644
--- a/Modules/ExampleModule/include/ExampleSegTool2D.h
+++ b/Modules/ExampleModule/include/ExampleSegTool2D.h
@@ -1,48 +1,80 @@
 /*===================================================================
 
 The Medical Imaging Interaction Toolkit (MITK)
 
 Copyright (c) German Cancer Research Center,
 Division of Medical and Biological Informatics.
 All rights reserved.
 
 This software is distributed WITHOUT ANY WARRANTY; without
 even the implied warranty of MERCHANTABILITY or FITNESS FOR
 A PARTICULAR PURPOSE.
 
 See LICENSE.txt or http://www.mitk.org for details.
 
 ===================================================================*/
 
 #ifndef ExampleSegTool2D_h
 #define ExampleSegTool2D_h
 
 #include <mitkSegTool2D.h>
 #include <MitkExampleModuleExports.h>
 
 namespace us
 {
   class ModuleResource;
 }
 
+// This is an example on how to add a segmentation tool to the standard
+// MITK Segmentation Views. Here's the crucial points to make it work:
+//
+//   * The name of the class MUST end in either SegTool2D or SegTool3D
+//
+//   * Derive directly or indirectly from mitk::Tool, for example
+//     mitk::SegTool2D is a typical choice for 2d tools and
+//     mitk::AutoSegmentationTool is a typical choice for 3d tools.
+//
+//   * Don't forget the MITK_TOOL_MACRO in the implementation file
+//
+//   * You don't have to provide your own state machine if the state
+//     machines of the MitkSegmentation module are sufficient, but if
+//     you do, you MUST provide both, the state machine and an event
+//     config file, for example Paint.xml and PaintConfig.xml. The
+//     file name of the event config file MUST be "equal" to the file
+//     name of the state machine, suffixed by Config.xml instead of
+//     .xml. The file name is passed to the base class constructor
+//     without any extension, for example simply "Paint".
+//
+//   * Look into ExampleSegTool2DGUI.h for an example of how to provide
+//     a custom tool GUI. The naming is important and basically "equals"
+//     the class name of the tool class, suffixed by GUI. Don't forget
+//     the MITK_TOOL_GUI_MACRO in the implementation file of the tool GUI.
+//
+//   * Ensure that the module containing your tool is loaded at runtime
+//     before the MITK Segmentation Views are opened. Otherwise it cannot
+//     be found. One way is to call anything from that module in a plugin
+//     with eager activation policy. Such plugins are loaded very early
+//     in MITK. For an example of how this works, look into ExampleModule.h
+//     and the org_mitk_exampleplugin_eageractivation plugin.
+
 class MITKEXAMPLEMODULE_EXPORT ExampleSegTool2D : public mitk::SegTool2D
 {
 public:
   mitkClassMacro(ExampleSegTool2D, SegTool2D)
   itkFactorylessNewMacro(Self)
 
   us::ModuleResource GetIconResource() const override;
   const char *GetName() const override;
   const char **GetXPM() const override;
 
 protected:
   ExampleSegTool2D();
   ~ExampleSegTool2D() override;
 
   virtual void Paint(mitk::StateMachineAction* action, mitk::InteractionEvent* event);
 
 private:
   void ConnectActionsAndFunctions() override;
 };
 
 #endif
diff --git a/Modules/ExampleModule/include/ExampleSegTool2DGUI.h b/Modules/ExampleModule/include/ExampleSegTool2DGUI.h
index 0b90fff..747334e 100644
--- a/Modules/ExampleModule/include/ExampleSegTool2DGUI.h
+++ b/Modules/ExampleModule/include/ExampleSegTool2DGUI.h
@@ -1,45 +1,47 @@
 /*===================================================================
 
 The Medical Imaging Interaction Toolkit (MITK)
 
 Copyright (c) German Cancer Research Center,
 Division of Medical and Biological Informatics.
 All rights reserved.
 
 This software is distributed WITHOUT ANY WARRANTY; without
 even the implied warranty of MERCHANTABILITY or FITNESS FOR
 A PARTICULAR PURPOSE.
 
 See LICENSE.txt or http://www.mitk.org for details.
 
 ===================================================================*/
 
 #ifndef ExampleSegTool2DGUI_h
 #define ExampleSegTool2DGUI_h
 
 #include <QmitkToolGUI.h>
 #include <QScopedPointer>
 #include <MitkExampleModuleExports.h>
 
 namespace Ui
 {
   class ExampleSegTool2DGUI;
 }
 
+// Look into ExampleSegTool2D.h for more information.
+
 class MITKEXAMPLEMODULE_EXPORT ExampleSegTool2DGUI : public QmitkToolGUI
 {
   Q_OBJECT
 
 public:
   mitkClassMacro(ExampleSegTool2DGUI, QmitkToolGUI)
   itkFactorylessNewMacro(Self)
 
 protected:
   ExampleSegTool2DGUI();
   ~ExampleSegTool2DGUI() override;
 
 private:
   QScopedPointer<Ui::ExampleSegTool2DGUI> m_Ui;
 };
 
 #endif