I recently posted a question here, for the first time in awhile. I wrote up the question, added an appropriate tag, then pressed submit. A red banner appeared at the top of the screen (I'm on the Android app), telling me that some specific tags were required. I was only half-done processing the message however when it disappeared. I clicked submit again hoping to see the message again, and was informed that I couldn't do that action again for another minute.
Why this was frustrating:
It's unexpected. As far as I know, no other site requires a tag from a specific set (although this is the only Meta site I've ever used).
The set of required tags isn't in a easy to read format. I knew that it was likely listing tags, so I was looking for a delimiter like a comma. By the time I realized it was delimited by spaces, the message had disappeared, and I didn't have time to process the tags.
The minute timeout seems really long. I know it's likely to prevent spammy requests on the server-side, but it's frustrating when all I wanted was to see the message again (maybe persist the message in a non-obtrusive way somehow?).
I'm red-green colourblind which may have slowed my processing of the message since it was on a red background.
Yes, this was due to unfamiliarity with the site, but I thought I'd voice my concern over usability. Feel free to disagree.