The reliable operation of protection systems depends on the correct settings of protective devices. The complexity of power networks and the large number of protection setting parameters make it extremely challenging to comprehensively validate the settings. This paper presents the design of a hybrid Rule-Based (RB) and Model-Based (MB) intelligent system termed Power system Protection Smart Tool (PPST), which is proposed as a solution for addressing the challenges associated with protection settings validation and performance checking. The RB element evaluates the settings using rules extracted from experts' knowledge and utility setting policies, while the MB element automatically interfaces with DIgSILENT PowerFactory to populate power network and protection system models to simulate and check the actual performance of the protection system under a variety of operational contexts. A case study is presented to demonstrate the operation of PPST, which shows that it is capable of effectively conducting the protection settings validation and performance checking task.