Not directly. The user agent string would (hopefully, if they knew what they were doing) make the bot appear to be a normal user, and it would post at a rate that would make it appear to be human. However, it would probably be very easy to identify by behaviour. The mod team has suspended and banned users that only ever posted nonsensical questions or responses, and the bot would fit into this category. The mod team would not be looking to say “this is definitely a bot, so we should ban them”, it’s more about looking to say “this user posts garbage, so we should ban them”.