Tips and Extended Tips provide help while you work.
Tips provide you with the names of toolbar buttons. To display a tip, rest the pointer over a toolbar button until the name of the button appears.
Tips are also displayed for some elements in a document, such as chapter names when you scroll through a long document.
Tips are always enabled.
Extended tips provide a brief description about buttons and commands. To display an extended tip, press Shift+F1, then point to a button or command.
If you always want extended tips instead of tips, enable the extended tips on LibreOffice - Preferences Tools - Options - LibreOffice - General.