Multi-Agent Systems have been proposed as a suitable conceptual and technological framework for building information systems which operate in open, evolving, heterogeneous environments. Our research aims at proposing design techniques and support tools for developing such complex systems. In this paper we address the problem of better linking requirements analysis to detailed design and implementation in the Tropos agent-oriented methodology with the aim to address adaptability issues. In particular, we revisit the definition of agent capability in Tropos and refine the development process in order to point out how capability specification can result from the integration of various analysis strategies. We also show how fragments of an implementation can be generated automatically from an agent capability specification.