Sub-Agent vs Tool-Agent in AI Harness Engineering
Sub-Agent vs Tool-Agent in AI Harness Engineering A sub-agent is another agentic process delegated a goal. It has its own prompt/context, can reason over steps, may call tools, and returns a synthesized result or handoff. Use it when the work benefits from independent judgment. Example: Investigate why the auth tests are flaky and report root cause plus fix options. A tool-agent is a tool-shaped interface that may internally use agentic behavior, but from the harness perspective it is invoked like a tool: bounded input, bounded output, narrower contract. Use it when you want a capability, not an independent collaborator. ...