Hello guys, I discovered Prefect a few days ago. I do have a few questions. I'm planning to use the Prefect Cloud as UI, and install the agents in different cloud providers on their always free tier. My main question is related to egress usage, are the agent polling periodically for work?

Welcome, Vio! Yes. Every 10 seconds by default, but you can change that in the settings. Check out the Settings section in the docs.

And how big is the payload?

I'm not sure.