Accessorys bugged or just useless?

[Daromar]

Iam wearing 3 Accessorys which give me in Sum 19 Endurance at the Moment. Endurance tooltips it decreases Stamina loss for actions Iam doing. My Field has a size that when Iam finished watering it, my Stamina is almost gone and there is not a notable difference with or without Endurance. I mean its 19 Endurance, there should be at least a notable Effect, right?
Same goes for mining Rocks. Iam not noticing any difference in the Amount of Rocks I can crush bevore my Stamina is gone.
So whats the catch? Does every Point Endurance decrease the Stamina Consumption by 0,1% or is it just bugged? I hate vage Information about Buffs.

P.S. The Fish Catching and Luring Buffs from Accessorys also have no notable impact.

[Gnollmar]

With 15 endurance, watering 9 fields costs 4 stamina, 1 endurance watering 9 fields costs 5 stamina ... so seems endurance lowers usage by endurance percentage. I was also going endurance, now I see how pointless it is.

[Totto]

Good Thing i wasn't going for them :-P
I have the Charming and Gift Giving + Animal Friendship Accessoires and here i can tell the Difference.
For Example if you get a newborn Animal and don't have the Accessory on, when it grows up, its missing like 2 Whole Hearts before it can start Breeding.
With the Accessory you can nearly instantly Breed the Grownup Baby