How we made GitHub Copilot CLI more selective about delegation

In agentic systems, more delegation isn’t always better. Imagine asking Copilot CLI to make a simple change. Instead of handling it directly, it spins up a helper agent that searches the repository, waits on a result, and stalls. Work that should have taken one step now takes three. While some tasks genuinely benefit from a specialist subagent—like exploring an unfamiliar repository, checking an independent area of the code, or running a long command while the main agent keeps moving—delegation isn’t free. Every handoff adds coordination overhead, tool calls, and wait time. If an agent delegates too eagerly, the “help” can become friction. We recently released an improvement to our agentic harness called smarter subagent delegation. This makes Copilot CLI more selective by helping the main agent: Stay focused when it can move faster on its own. Delegate when a specialist creates real leverage. Parallelize work when tasks are truly independent. Smarter subagent delegation has now rolled out to 100% of Copilot CLI production traffic. If you want to get started today, simply update GitHub Copilot CLI by running the /update command in your terminal to version 1.0.42 or later. In a production A/B test, this improvement reduced tool failures per session by 23% , including a 27% reduction in search tool failures and an 18% reduction in edit tool failures. It also improved total user wait time by 5% at P95 and 3% at P75, with no quality regression . Here, P95 captures wait time near the slowest 5% of sessions, while P75 reflects wait time toward the slower end of typical sessions. This means fewer unnecessary handoffs, fewer repeated searches, fewer failure-prone tool paths, and less waiting during long-running coding tasks. In this post, we’ll walk through how we identified unnecessary delegation in Copilot CLI, what we changed to make delegation more selective, and how we validated those changes through offline evaluation and production A/B testing. We’ll also show why th