It means 1.5× dmg for any primary skill (richocet, barrage, teleport, trap, anything that is primary skill). It should work but it’s like using multi attack or Push the Limit for those skills. You’re right. Maybe it’s bug that stat page don’t show increase in dmg just like the discordance, multi attack and damage.
Discordance can work with skilled but only for primary skills that have the special skill CD, mana cost and Dmg but not special skills with primary skill Dmg, CD and mana cost. It’s still good in a way though.