Problem
I'm always frustrated when I see a bunch of icons I don't understand immediately. Despite being a designer and avid-tech-person, I struggled to understand (right away), what each icon would do.

Solution
Ideal solution is to add labels along with icons. If that's not possible, then add a tooltip that shows up immediately when I hover on the action-icon-button and persist till I don't take my cursor out.

Notes

• Spotify reference when you hover the 'heart' icon. (They still don't load the tooltip immediately.)
  

• More reading on this topic - https://www.nngroup.com/articles/icon-usability/