Tool Persistence, or ToolDataStores are something that have became not as popular among new coming developers, and, have become quite the challenge!
But, thankfully, there have been methods of DataStores that are easy to use, and simple to operate with! I will provide you with some helpful links to checkout! These links are what helped me, and will help you if you put the time in to read them!
This is a DevForum Post that I found useful!
All of these links should provide you with enough information YOU NEED to start creating your very own DataStore system for tools, and more!