I mentor students on research projects. I think it can be fine to use the word “just” in this context exactly to telegraph that I think a particular task should be easy. Student says, “But what about X?” I might say, “Oh, just do Y.” It’s fine if they feel the tension of me knowing how to do something and thinking it’s easy and them not. The key part is providing a supportive environment so that they know they can as…
Just a few weeks ago at work, one of the TLs told me I should ‘just do X’, and when I pushed back saying it’s going to take a few weeks, he said ‘oh it’s just a couple of lines, I can do it in 10 minutes’. I challenged that. 5 integrations and 2 weeks later we had a first working version, that caused more harm than good in the end because of an assumption that didn’t hold.
I think easy things might be easy in theory, but not necessarily in execution. So when a student comes to you, I suspect they have thought about theory, but find the execution hard because of the knowable unknowns they are not aware of and you are. Many times people don’t even propose things that might seem obvious to them out of fear they might say something stupid. Indicating something is easy in a demeaning fashion is bad. Phrasing it differently has a different effect. E.g. Oh, I think that might be solved with X. It should be relatively straightforward. Look at the work I did , it should match your use case.