On the activities resume, do I need to describe what I did or do I only need to write out the club? e.g. I did robotics team, so do I need a sentence or two describing my role on the team?
Sort of depends on how many activities you have.
But if you were a typical member, say “member”. Indicate when (e.g. 10,11)
If you were the Team Lead, or Treasurer, or the Fundraising lead, say so.
If your team was very active/successful, you can add something brief like “local and state competitions” OR “advanced to national competitions”; “several team awards”. These reveal something about the level of time/commitment.