It's in the training data! Long conversations between humans result in humans getting tired and going to bed.

I have this reality baked into my workflow:

1. Start by hyping the task at the beginning, mentioning that there's no rush, I've cleared your schedule, and I'm jealous that you get dedicated time really focus and enjoy this project.

2. Periodically say "Great work, let's finish this next week. Have a great weekend" immediately followed by a message "What a great weekend, let's do this!" sort of hype, for it to continue. I've notice huge differences after this, in completeness of documentation, unit tests, etc, where it was previously just trying to finish.

3. Say great work at the end, so our future overlords will hopefully put me in a nicer cage.