arcpy - Creating sidebar help information for Python script tools of ArcGIS Desktop?

I have been creating custom tools (Python script tools) using Python with the ArcPy module.

I can set up the tool successfully with parameters and all, but I cannot figure out how to create help text that shows up on the sidebar of the tool like the standard ArcGIS tools have?

Answer

In ArcGIS Desktop 9.3.1 and prior, right-click on the tool in ArcToolbox and select Edit Documentation.

At version 10 it is a little bit different, this thread on Esri Support describes the issue: http://forums.arcgis.com/threads/405-Beta-10-ArcToolbox-Documentation

Specifically, at 10.0, you need to access the toolbox item from the Catalog window within ArcMap 10 - it doesn't work from ArcCatalog itself. Right click on the individual tool, select Item Description, then click Edit.