This is a pretty common question to a Scrum Master. Below are a few points based on current industry expectations.

#1 Now Scrum Master is no more a non-technical person who runs a few Sprint ceremonies, he is also responsible as Project Manager, QA & Technical Manager, who takes care of the Quality, technical & Product requirements. If possible he plays the role of BA also.

The more knowledge you have the better control you will have.

#2 Track & Resolve all impediments.

#3 Motivate & guide the team on better planning, and process following.

#4 Understand the team & have mental connection.

#5 Arrange all required training.

#6 Takes care of quality in each & every stage of the development cycle.

#7 Conduct all Sprint & other Ceremonies.

(1- Backlog Refinement 2-Sprint Planning 3- Daily Scrum 4-Sprint Review & Demo 5- Retrospective)

#8 Before Daily Scrum, make sure Jira’s status is updated with the latest update in the comment section.

#9 Sprint Capacity Planning & make sure 100% allocation.

#10 Make sure team members leave should not hamper the Sprint Commitment.

Motivate to convert unplanned leaves to planned leave.

#11 After meetings, review demo, note down MOM with action item & owner. Circulate the same with required Stakeholders.

#12 End-to-end (E2E) responsible for Software Development Life Cycle (SDLC)

Starting from Project Planning to Production Release.

#13 Find all possible solutions to smooth project execution, Quality control, Process & Performance Improvement etc which will give confidence to all stakeholders.

#14 Assist PO or BA on Product Backlog, User story writing.

#15 Create & maintain Jira Board & Reports.

#16 Before Daily Scrum go through all user stories & note down all points of action or discussion.

#17 Scrum Master helps in Hiring & Onboarding of team members.

#18 Scrum Master is SPOC (Single Point Of Contact) between the team & different Stakeholders.

#19 When the team raise any Clarification, Scrum Master makes sure the question is Technical to the point so, that others can understand without any further discussion.

#20 Scrum Master controls Scope change within the Sprint.

Still, if you are not convinced with the above activity then remember, in some teams & organisations, Scrum masters manage more than one team or project, two teams are pretty common to manage which is 50% allocation of the Scrum Master. All of the above activities will multiply two times.