A lot of agent systems look like org charts.

There's a router at the top. Under it, a refunds agent. A shipping agent. A billing agent.

Each one has its own prompt, its own tools, and its own context window.

It feels organized. It also means every handoff is a summary of a summary.

Every handoff loses something.

This week, Anthropic published Building agents: When to fold subagents into your main agent loop . The opening line is the whole argument: "using fewer subagents in favor of progressively disclosed context and tools can improve quality while reducing cost and latency."

The idea is simple. The agent sees short descriptions of skills and tools up front. The full versions load only when needed.

Anthropic gives three reasons. Shared context produces better answers. Progressive disclosure prevents context bloat. And models are more capable now, starting with Opus 4.5.

One detail stood out.…