Technology Radar
Subagents for better context management is the practice of delegating work to subagents to keep it out of the orchestrating agent's context. Exploration, tool output, retries and intermediate reasoning stay in the subagent, and the main session receives a short summary. Most people first use subagents to run tasks in parallel or form a role-based team of coding agents. Protecting the orchestrator's context is another reason to use them. Whatever remains in the orchestrator's context competes for its attention on subsequent turns. Pulling a subagent’s full transcript into the main thread to check its progress undoes this benefit. Useful guidelines include running two to four subagents at a time and keeping tasks that require the same understanding of the code within one agent, so multiple agents don't each have to rebuild that understanding.
Using subagents to protect the orchestrating agent’s context is a form of context engineering that’s easy to try because most coding agents support subagents, and the change is largely in the instructions. We've used cheaper models for subagents handling narrow tasks such as research, potentially reducing costs compared with blanket frontier model usage. We're placing the technique in Trial because its benefit hasn't been measured systematically. The evidence so far comes from practitioners' accounts of their own sessions, without detailed token accounting. We've also observed that the same model with the same prompt uses subagents differently depending on the harness. Teams trying this approach should use context profiling to check whether the orchestrator's context actually shrinks.
