Argumentation theory, implemented through a set of software agents that reason about Web Services, can improve Web services' performance through the help of communities. An argumentation system comprises of a logical language and defines arguments, attack relations between arguments, and terms of acceptability. Web services can use proportional Horn logic and the logical inference to build arguments attacking the addressees' arguments. Generating arguments and converging toward agreements in persuasions and negotiations are faster when the agents' knowledge bases are small. Whenever an event is posted, the addressee uses its argumentation system to find a plan that would handle this event.