Description actually has actually been in all versions of FTM since FTM 2008 and all the Mac versions
You can display a description field for every fact or as many as you choose
It fills a great need
For example it can be used to record a church, hospital, street address, cemetery and similar details that expand the place data, especially if you use the resolve place names.
Description also has fastfill so you can get your descriptions of a place, address etc consistent. This helps when running custom reports.
Some people use the Description field to record source information, and while it may work for them, they miss out on all the source report capability.
But the description field is a very useful note field associated with the Place field