The existing Learning Management Systems (LMSs) are profoundly effective in empowering the organization of e-learning, however, lacking in usability and learnability. The complex navigation and an immature search system are catalysing the issues that needs vigorous improvement. This paper aims to enhance the usability of LMSs by introducing an intelligent multi-agent based voice-enabled virtual assistant, named Scavenge. The Scavenge can work with LMS to speed-up user tasks through natural voice-command (or text). It can perform many internal and external actions without a mouse or keyboard clicks, and capable to provide the results of user search queries. A prototype system was developed with Moodle LMS and conducted a usability test based on ISO/IEC 9126-4 usability metrics that are effectiveness, efficiency, and satisfaction. A group of University students were selected, who were involved in the usability testing of the proposed system. The results have shown that the proposed system has a positive impact on students' performance and can enhance the usability of LMS. The approach and techniques used in Scavenge are novel and innovative that will be a valuable contribution to the overall field of knowledge.