When a request comes up in the group chat, I reply first.

When someone posts an urgent request in the group chat, sometimes I reply as soon as I read it, and only then remember what I already had planned.

Scenes

When a request comes up in the group chat, I reply first. — One evening, someone asks in the group chat for help organizing some files. I read the alert and send, “Sure, I’ll do it,” then remember what I have planned for tomorrow.
I replied before checking — In the group chat, it can feel like both the person asking and the coworkers reading are waiting for a reply. It’s hard to be the only one to hold back, so I send “Sure” first.
A request isn’t the same as taking on a task — Receiving a request and agreeing to take it on aren’t the same thing. Before checking your schedule and what’s involved, your reply doesn’t have to be a decision.
Leave room to check in your reply — Tonight, before replying, I’ll look at tomorrow’s schedule first. Writing, “I’ll check my schedule and get back to you,” lets me hold off on agreeing to take it on.
You can follow the same steps tomorrow — Even after saying you’ll check, the request may still feel like a burden. You can look again at what’s weighing on you, whether it’s your schedule or what the request involves. You don’t have to decide right away.