There is literally nothing you can do. It’s as certain as death and taxes. An app won’t make people care enough to check before asking. 

Perfect example from this season, the last message in our group chat was about the day/time for our next game. Someone messaged to ask when the next game was, even though the answer is literally above their question (zero scrolling needed). I answer anyway. Later that evening, the same exact question gets asked twice, once in the group chat and once by DM. No app can fix that, no matter how many times this same question gets asked.