An innovative and very detailed end-to-end system modelling tool has been developed and applied to test on simulated data the actual measurement capabilities of any generic high frequency (HF) magnetic diagnostic systems. The main goal of this rather complex tool is to obtain estimates of the intrinsic measurement uncertainties and then assess the actual vs. intended system measurement performance for correctly detecting individual components in the frequency spectrum of HF magnetic instabilities in the plasma. This has paramount consequences not solely for off-line analyses but also, and more importantly, for any real-time application where, as an example, the mode frequency, amplitude and {toroidal, poloidal} mode numbers are used to determine whether, and which, corrective actions need to be taken to stabilize the discharge.The algorithm has been applied to some of the various ITER HF magnetic diagnostic systems, most notably the AJ (LTCC-1D sensors) system as currently designed, hence providing specific confidence levels and error bounds for detecting the modes highlighted in the ITER measurement specifications. Additional analyses have been performed for the TCV and JET HF magnetic diagnostics, providing further constraints on the results obtained with these systems.