1. A computer system for automatically generating service documentation based on usage of a web service, the computer system comprising: one or more computers including: one or more input/output components configured to operatively communicate with a network; a processor operatively coupled with the one or more input/output components and configured to execute computer-executable instructions; and memory storing one or more computer-executable instructions that, when executed by the processor, perform operations configured to: capture network traffic communicated via the one or more input/output components including one or more actual requests to a service endpoint of the web service and one or more actual responses from the service endpoint of the web service; analyze the captured network traffic using one or more machine learning algorithms to determine one or more operations that are available at the service endpoint, one or more input arguments that are accepted by the service endpoint, and one or more output arguments that are provided by the service endpoint, including using the one or more machine learning algorithms to determine one or more mandatory input arguments that are necessary for successful operation of the web service based at least partially on analysis of (i) one or more output arguments that indicate an unsuccessful operation of the web service, and (ii) one or more output arguments that indicate a successful operation of the web service; generate metadata based on the analysis of the captured network traffic for the service endpoint that identifies the one or more operations, the one or more input arguments, and the one or more output arguments; automatically generate service documentation for the web service based on the metadata, the service documentation including at least identification of the one or more mandatory input arguments that are necessary for successful operation of the web service determined using the one or more machine learning algorithms; and communicate the service documentation for the web service to a client device.