Meeting That Should Have Been a Message

I got this backwards twice last month.

First I scheduled a thirty minute call to discuss something that needed one paragraph. We spent the first ten minutes on pleasantries and the last twenty on something that would have taken four minutes to read.

Then I sent a long message about something that actually needed a conversation. Three days of back and forth, misunderstanding layered on misunderstanding, when ten minutes of talking would have cleared it.

The medium matters more than I usually admit. Some things need the back and forth of a real conversation. Some things just need to be written down. And I pick wrong constantly because I default to whatever is in front of me.

How do you decide whether something should be a message or a meeting? And do you have a rule or is it instinct?