Call handling decisions are made based on explicit information such as caller ID and/or implicit knowledge inferred from previous interactions. Our previous work showed that people often answer calls to find out the reason behind the call. This suggests that the provision of explicit information regarding what a call is about or under what circumstances is it being made can be of value in call handling decisions. To explore this concept we developed Telling Calls a prototype application for cell phone users to provide and receive call related information. We present the design rationale and lessons learned from qualitative accounts of users' experience with the application in their daily life. Our findings confirm the utility of our design and suggest ways in which we can improve the design to support informed call handling decisions in mobile phones.