legolodestone addresses the question of what was daily life for a jester. And currentmadmen discusses It's often said that the jester is the only one that can speak truth to the king. Historically speaking though, has that ever been the case, using comedy or satire to persuade or inform an absolute monarchy or similar form of authority?

This should help confirm that there really were jesters, jokers, and fools in medieval courts. There are a number of great threads on this in r/AskHistorians