The agile software development (ASD) replaced other traditional approaches such as a waterfall or incremental, in which there is no instrument used for changing requirements. Agile is a better method to run the company and economy, as it satisfies the clients via timely and continual delivery of software. Nowadays, it has become the most well-known technique because it accepts the change requirements of the projects. Hence, it is difficult to get precise cost estimation because of continuous changes. Nevertheless, we acknowledge that in the context of ASD, various effort estimation techniques have been reported. However, to the best of our knowledge, existing effort estimation techniques/models do not include the additional factors needed to compute accurate effort estimation in the context of ASD. It is beneficial to identify all the factors contributing to the cost overhead to improve the agile effort estimation process. Thus, the research aims to find out important and relevant factors in the ASD context. Moreover, the most common challenges and reasons for improving effort estimation in ASD are also highlighted. We believe that the results of this research could be helpful to assist the practitioners working in the ASD environment.