Is the intent that only melee weapon attacks can knock foes unconscious?

@TinyConstructHowdy! Is the intent that only melee weapon attacks can knock foes unconscious, or can mele spell attacks as well? The rule on knocking creatures unconscious is intentionally not limited to weapons.

— Jeremy Crawford (@JeremyECrawford) November 6, 2014

@TinyConstructSo melee range spells work. I think this confusion in our group stems from past editions not treating spells as “attacks” Yep, a spell attack works if it is called a melee attack in its description.

— Jeremy Crawford (@JeremyECrawford) November 6, 2014