This paper presents a set of restrictions based on the instantaneous control effort analysis in the context of the controller tuning method introduced in [1]. First, an overview of such method is given, which is based on the design of a reference model whose dynamics are determined by the values of the integral and derivative constants. Afterwards, the internal stability of the control loop is studied and analytical restrictions are given by means of the Routh-Hurwitz criterion. The results of the control effort stability analysis are presented for three different types of systems: a first order system, a second order system, and a first order plus dead time (FOPDT) system. Finally, it is shown that the experimental results validate the effectivity of the controller and demonstrate that the imposed restrictions are indeed fulfilled.