Agent Mail is another favorite. It lets agents talk to each other.
Why I use it
I prompt: Get a second opinion on this from Fable 5 and Grok. Sort this out through agent_mail. Fable 5 is the coordinator. Then the agents go ahead and discuss the topic in detail, back and forth.
I experience that different models approach problems from different angles. Agent diversity is a real thing. Just like humans.
This was more important back when the models were weaker. Today, SOTA models one-shot excellent solutions more often. But I still find asking agents to iterate through Agent Mail very valuable.