The Component Wizard defines the minimum required information for a connector or a device to be assigned using NX. Beyond that you would need to import a component file (*.cmp) or a PLMXML file from a 3rd party schematics program. The column headings in the Component Navigator are defined using the ugroute_elec.cfg file (C:\Program Files\Siemens\NX 10.0\UGROUTE_ELEC\rlist). To determine which display format is being used, right click in the Component Navigator and choose Properties and it will be listed at the top of the dialog. This dialog is also used to define which Import and Export formats are used in the ugroute_elec.cfg when importing from a 3rd party schematics program, or when exporting from NX.
So, you can't define "Description" using the Component Wizard. Having assigned your connectors, you could export the content from the Component Navigator as a cmp file, edit each line using a text editor and import the edited cmp file:
!Component List File Format = Example !Type = comma_delimited !part_name, unique_id, connector_id, signal, description 10_pin_green_round, abc123, Con1, , Community Example