In recent years, Agile methodologies have increased their relevance in software development, through the application of different testing techniques like unit or acceptance testing. Tests play in agile methodologies a similar role that in waterfall process models: check conformance. Nevertheless the scenario is not the same The contribution of this paper is to explain how the process can be modified to do early identification of hidden requirements (HR) using testing techniques in agile methodologies, specifically using failed tests. The result is an optimized agile process where it may be possible to reach the desired level of functionality in less iterations, but with a similar level of quality. Furthermore it might be necessary to re-think process elements role, e.g. tests, in the Agile context not assuming waterfall definition and scope.