This minecraft mod implements armor for the wolves. A wolf can't really decide whether to wear the armor or not since they are always spawned with the armor (assuming you've enabled the add-on). The armor protects them better and this is most noticeable by the fact that they have more health. As a player you're also given a few more uses for the wolf (e.g. riding).

How does it work?
The Armored Wolves replace the ordinary wolves in Minecraft. If you find one out in the wild then you can tame it with some bones.
iOS / Android: Long press on the wolf and press Tame (make sure you've got a bone in your hand)
Windows 10: Right-click on the the wolf with a bone to attempt to tame it
Tamed wolves have five times more health than an ordinary wolf and it can also be used for things such as protection and riding.

Give a saddle to a wolf to ride it. You can also give it a horse armor to upgrade the armor to Extra Protection.

General Armored Wolves Info:
Wild Armored Wolves
Health: 10 hearts
Tame with bones
Tamed Armored Wolf
Health: 50 hearts

Give saddle to ride it
Give horse armor to upgrade armor to Extra Protection