Here's what would piss me of the most:
"Hey, I got a question. Do you have time to talk?"
Me not knowing what this is about or how long it would take to answer this mysterious question of yours: "not right now, gonna text you in the evening"
Me (later): "So what was your question?"
"I wanted to go to that concert on Friday. But now all of the tickets are gone and I'm going alone, lmao"
I HAD enough time to answer a simple yes/no question. I hate it when people ask if I have time to text. At least give me a fucking hint like "hey I got a short question: its about the concert on Friday". Asking if one has time to text causes the most social friction IMO but the least visible friction (to you).