Currently Polonia has 2 loot-related skills:
- (Past rank 7, IIUC) 100% chance to increase tier of non-stolen loot. Not level-capped.
- 50% Chance to steal more loot, capped at T11/T12 depending on talent tree.
Her current skill text says "50% chance to steal super valuable items from monsters" which really only describes that second skill.
The first one should be mentioned in her skills tab, and as separate line-item so it's more obvious why she should be used-- It's the difference between "Why you should send her out in ToT A LOT" and "Why would you use her in ToT".