Like sand - doesnt give a clear description

Deformed Antler: Like Sand
Your creatures ‘cost health instead of mana’ are now 50% more potent.
Since sentence looks crippled for me i only can make guesses:
makes spell thats cast based on hp give better effects, if possible, more damage, more stats, more barrier? (it affects gems that have property)
makes health based spells cost less (it affects property itself, not gems)