There are item descriptions (somewhat). The only way I found how to get them displayed is.
Using the / key
This will prompt:
Specify unknown object by cursor [ynq] (q)
This will allow you to click on an item on the ground
For a dagger this generates a message like this
a weapon (dagger)--More--
More Info [yn] (y)
Selecting y will give you additional info about the item usually it's some quote about the item. For example the dagger we used above gives us a line from Macbeth by Shakespeare about a dagger.
The other way is \ key will show you your discoveries, an example of that would be
potion of blindness (golden)
Show you that you know that a golden potion is a potion of blindness