Scope subagents to only the tools they need — and the July 2026 fix stops full-task re-delegation

Towards Data Science·medium signal

A subagent starts with a clean context window and only the tools you assign it, so the main agent never pays context cost for tools it doesn't directly use; equip each subagent with its own MCP servers and skills. Anthropic's July 2026 update also fixed a failure mode where subagents re-delegated their entire task to yet another subagent. Give each subagent a narrow tool set and a concrete sub-goal to get isolation benefits without the re-delegation loop.