It is just as easy to tell a reader too much as it is to tell them not enough. Neither is good and writers are challenged to find that perfect middle ground.
Let’s start with the old “show, don’t tell” axiom. We don’t want to tell the reader a character is angry. We want to show the angry behavior so the reader infers the anger for themself. Otherwise, you’re “telling.”
So, here’s an example of showing a feeling: “He slammed his cup down on the white tablecloth, splashing hot coffee toward her. Standing up, he kicked the leg of his chair, turned and left her alone in the restaurant.”
Envisioning the scene is a far more impactful way for the reader to feel the feelings your character is experiencing. You don’t need to be told he was angry. That is obvious. Of course it takes more words and effort to paint the scene than simply saying the man was angry.
But the writer can go too far in showing. We can use too many words, battering the reader over the head with examples. Once they have the idea, really visualizing the scene and feeling the anger, that is enough. If you go on too long, you risk offending or boring the reader. That is the challenge of pacing, of maintaining forward progress. Say enough to convey the feelings and then move on.
Of course the opposite is also a problem. If you don’t provide enough information, that is arguably worse. The reader may not understand the scene at all. Insufficient information leaves the reader confused. They will be puzzled when, a few scenes later, an angry husband serves his wife divorce papers. Or they may never get to a later scene. When a reader is lost and confused, they may close the book and not return.
There is no formulaic answer here, as in “give two examples and move on.” It is a matter of finding the right balance, showing enough, but not over-doing it.