Take hold of a running agent, start a fresh conversation, or direct its subagents. Across nine AI harnesses, the same command can mean different things.
You press Enter while the agent is working
Five of the nine steer. DeepSeek Harness and Grok Build queue separate follow-up turns by default; Hermes interrupts the active run. The Goose CLI only reads prompts between runs, so mid-run Enter is not a control. OpenClaw used to queue too, but changed its shipped default to steering in later releases. That is why this card exists.
Eight of the nine ship subagents, and those eight spawn them the same way: the model decides. Pi deliberately leaves subagents to extensions. What separates the tools is what happens next — whether you can watch a child work, or only read what it chose to tell you when it was done.