Haste increases attack and spell casting speed, adds additional damage and healing to DoTs and HoTs, and reduces the GCD. As a Brewmaster, Haste increases the speed of your Energy regeneration.

Agility increases your attack power and the damage dealt by your abilities. Further, Agility slightly increases your chance to Dodge.

Mastery provides a passive bonus to your character based on your specialization. Mastery Elusive Brawler increases your dodge chance every time you are hit by an attack until your next successful dodge while also increasing your attack power.

Versatility increases your damage, healing, and absorption done and decreases damage received.

Critical Strike increase the chance for your spells and attacks to critically hit for additional damage and healing.