Using zone calculations in the FLAPS (the full-potential linearized augmented-plane-waves) model, information is obtained on the energy, charge and spin characteristics of Pt$_{1-x}Me_{x}$MnSb alloys ($Me$ = Ni, Au; $x$ = 0.0–1.0). As established, with an increase in the concentration of nickel or gold atoms the interatomic spatial density of electrons decreases, covalent bonds weaken and the binding energies of atoms in alloys decrease. As found, the dominant contributions to the formation of magnetic moments are made by 3d electrons of manganese atoms, and the polarization of electrons at Fermi levels depends on the composition of alloys.