Gricean maxims prescribe cooperative speakers to make their utterances maximally informative so that listeners have the highest chance of understanding the utterances. At the same time, speakers are expected to save effort and not produce descriptions that are more explicit than necessary. In this work, we first ask how predictability of the described events affects the choice of anaphoric referring expressions. We show that speakers prefer phonologically overt descriptions, such as definite NPs, when they refer to agents that behave in an unexpected way. We further test how the interpretation of referring expressions changes depending on the listening conditions and prior expectations about the plausibility of an event. Our work shows that the speaker's extra effort in choosing a more phonologically overt referring expression is justified by listeners' behavior: they report having heard an utterance which is more plausible than the originally spoken utterance and which contains additional phonological material.