I picked the Coach role for this exercise and here is what I found:
• Work within a delivery team to provide mentoring of agile technical practices
• Guide and teach others using pair programming for:
○ Test driven development
○ Behavior driven development
○ Continuous Integration/Continuous Delivery
○ Automated testing
• Teach architectural principles through the process of emergent design
• Participate in team ceremonies as both a team member and mentor
• Provide observations and suggestions for improvement
• Work with other team mentors and coaches to collaborate on maturing the team and organization agile practices
• Assess and report outcomes to customers and management team.
• Help prepare teams to apply agile methodology in other industries.
• Develop a plan to prepare teams to learn agile methodology and train staff.
• Provide the leadership and knowledge needed in order to effectively expand or introduce agile methodology.
• Strong experience in agile principles and technical best practices
• Strong automated testing skills
• Experience with the automated build process, unit testing and source code analysis tools
• Knowledge of Continuous Integration/Continuous Development
• Ability to assess and coach team to optimal agility
• Team oriented and possess strong interpersonal communication skills
• Comfortable working in a variety of social and business environments and multiple technology stacks
• Have excellent time management skills
• Capable of making quick and effective decisions
• Be a strong leader who is capable of training others
So, this is a long list of activities and skills required for some job postings I found online. What seems to stand out from these is that this kind of role requires knowledge from a wide range of technologies. I do not think that deep understanding is required but at least some knowledge needs to be present to take the role.