Completeness (left panel) and purity (right panel) of the AMICO KiDS-DR3 cluster catalogue as a function of the redshift, z, and of the intrinsic richness, λ^*. The completeness is a function of the true λ^*, i.e. , while the purity is defined as a function of the observed intrinsic richness, . The shaded area in the right panel highlights the bins excluded from the number counts’ analysis, i.e. for  < 20.