one of the dictionary for the word exaggerate is to make an overstatement. what would the connotation be if someone warned a friend about roger because he exaggerates.

Roger is trustworthy, roger is a person who tells lies, roger is someone you can rely on, or roger minimizes what he says

The connotation would likely be that Roger is someone who tends to make overstatements or exaggerate the truth. It may suggest that he is not always completely honest or accurate in what he says.