Good skills to coach team how to follow agile scrum, which really works.
Understand the basic fundamentals of iterative and incremental development.
Strong knowledge of Scrum theory, rules and practices.
Knowledge of other Agile approaches, like: Kanban, Crystal, FDD, XP, etc.
Knowledge about other methodologies other than AgileScrum, so that he can explain other methodologies to motivate his team.
Basic knowledge of software development processes and procedures to understand his team needs.
He should have knowledge about Agile techniques like: User Stories, Continuous Integration, ATDD, TDD, Continuous Testing, Pairing, Automated Testing, Agile Games.
Ability to take and understand his commitment to deliver the product on time.
Know about the value of metrics and incremental delivery.
Knowledge about tasks, backlog tracking, burndown metrics, velocity, user stories etc.
Familiar with common development practices, Service oriented environments, and Agile practices.