It claims it did something, but only did partially. Did not actually verify. Every time I discover such things, I explicitly ask it to write to instructions. It helps.

This one i do not call it mistake. It did a job but did not meet my standard. In those cases i gave it good examples and asked it to learn from those.

And how long until you realize there were mistakes?

It depends how frequently you interact with those bots. I interact on a daily basis, and it took me a few days to realize strength/weaknesses of those bots. I also keep an eye on the grok bot team workshops and learn from their practices. They share a lot. There is a bot called “ dr eggbot” on marketplace, which you can use to create other bots. That bot was created by one of the leading grok bot team member.