To drive a photoredox reaction thermodynamically, a MOF photocatalyst should have its ionization potential and electron affinity properly aligned with the redox potentials of such a reaction. Focusing on the case study of water splitting, we have translated these observations into six descriptors that we can compute to evaluate our MOFs for photocatalysis: charge carrier mobility, charge separation, charge-transfer character, visible light absorption, and band alignment to the hydrogen (HER) and oxygen (OER) evolution reactions.