A translation should not sound like a translation. It should sound like any other good, natural speech or writing in that language. Accuracy is measured by the degree to which users of a translation get the same meaning from it which the original text had. Accuracy can be determined by field testing the translation among a wide range of speakers of the target language. In fact, it often reduces accuracy.
Meaning is found more than just in words.
It is the total expression of an utterance, including meaning which is found in the words, but also in the syntax of how the words are connected to each other, how the resultant phrases are connected to each other, and how sentences, paragraphs, episodes, and discourse segments relate to each other. Meaning is also often not explicitly expressed in one language, because there are cultural clues making it unnecessary to do so. But that implicit meaning is just as much a part of the meaning of an utterance as are the explicit words and syntax. Meaning is also found not just in the denotations of words, but also in their connotations. A good translation will reflect, to the best degree possible, the connotations, rhetorical impact, and emotive style of the original text.