Yes, I agree there is definitely a bug in the tooltips when Barkskin is applied to our party members with AC<16, as per the screenshot of Gale I posted somewhere above which says something like "Base AC 10, Barkskin +6, Dexterity +2", when either the dexterity bonus shouldn't be mentioned at all or the calculation of AC without Barkskin should be given and then the Barkskin increment given as the difference between that and 16. At the moment, it's really not helping given that there can easily be confusion about how Barkskin works already!
I think that, ideally, the tooltips should read in a way that displays whatever method of AC calculation you are using already, plus the difference between that and 16 attributed to Barkskin - so, an otherwise unarmoured draconic sorcerer, for example, the tooltip might read "AC 16 (Base AC 13, Dexterity +2, Barkskin +1)", and the extremely clumsy druid might have "AC 16 (Base AC 10, Dexterity -3, Barkskin +9)"
This would convey the function that Barkskin is actually fulfilling more clearly, I think.
