I'm hard pressed to answer this question (and I suspect I'm not the only one, seeing as it's been so long unanswered) without knowing more precisely what you mean by "tell the truth." A work of literature can be said to have various meanings, some of them mutually exclusive, and few (if any) constraints on viable interpretations. So in that sense, it would tell the truth, because the range of what it "tells" is so very broad. But it would be the same with the visual arts, wouldn't it? If "telling the truth" is understood to be some kind of correspondence with an external state of affairs, then it seems other areas of knowledge (mathematics, for instance) would "tell the truth" better. Aesthetics isn't my area, and so far I'm only dabbling in Phil of Literature; I'm afraid I can't do better than this for an answer. But it is an intriguing start to a conversation. I hope you pursue it.