How can I set the description underneath a custom module?

I added a custom module to the tools tab. When I click on tools, it displays all the modules and their descriptions. I.e.:

Reporting
This section displays a list of report categories. You can either create new report category, or edit or delete existing ones. For each report category, you can edit, delete, clone or export individual report or create a new one.

How can I set this for my custom module? It just states:
[ModuleName]
"Tools.[ModuleCodeName].Description"

Thanks!
Joe Hoppe