By default, Get-ADUser (provided by ActiveDirectory module which is part of the free Microsoft RSAT tools) retrieves only a few default properties. To get more information, use the –Properties parameter, and specify the properties you are after.
To get a list of all AD users with their notes and description fields, try this:
#requires -Modules ActiveDirectory Get-ADUser -Filter * -Properties Description, Info
If you don’t know the names of available properties, use “*” instead to retrieve all available properties.