Keegan-Michael Key joined a very lucky group on the TMZ Celebrity Tour ... offerin' up advice on how award shows can evolve so comedy bits don't drag people down.
Keegan hopped on our bus in Bev Hills ... and as his wife and writing partner Elle kicked it on the sidewalk, he offered up some tips on cringe-worthy humor during these awards shows.
KMK put it plainly -- you can make a killer joke that has a positive message ... but bringing someone down should be out of bounds.
He's pretty clearly referring to last week's Emmys ... where Jimmy Kimmel was dragged for "passing out" on stage as Quinta Brunson accepted her award for Outstanding Writing for a Comedy Series.
After finishing his TMZ Tour "Ted Talk," he entertained passengers with a throwback from 'Key & Peele' ... breaking out his substitute teacher character that he debuted a decade ago!!!