Offload file discovery and grep to a dedicated subagent so the parent never sees raw tool output

HumanLayer·medium signal

Rather than letting your main agent run grep/glob and bloat its own window, ACE-FCA dedicates a subagent to search/summarize and returns only a structured result: goal achieved, files involved, key findings, unknowns. The parent reasons over clean output, not thousands of lines of raw matches. This is context isolation as a deliberate architecture, distinct from permission-scoping — it protects reasoning quality, not just access rights.