What are some of the best tools one should know in order to stick out as a CSM?
Working knowledge of a CS tool is helpful. Also, since Sales and CS teams work very closely together, having working knowlege of CRMs like Salesforce where you can create reports to analyze pipeline etc is helpful. As a CSM, it is also incredibly helpful to know your company's productions and solutions intimately so that you are able to connect the dots between your customers requirements and your company's offerings. Last but certainly not the least, CS certifications are definetely helpful in validating your CS skillset. There could be others but these would be good for a start.
I am not listing the basic ones that all CSMs should know. But the list that will stick you out -