Moment tensor inversion is a valuable tool for understanding what is happening below the surface during hydraulic fracturing or reservoir monitoring. The reliability of the inversion is critical to estimating the source mechanism, and the condition number is used as a measure of accuracy. The lower the condition number, the better the inversion. But how to estimate the maximum condition number to provide a reliable inversion result? I present 3D simulation results of the condition number around the source location and how real seafloor noise and the receiver position error affect the inversion misfit. These simulation results can be used for planning seismic monitoring projects to find an optimal array geometry and to evaluate the inversion accuracy at a given target area.