Runtime rejects spawn_subagent kind=computerUse until web/DOM/MCP
was tried this turn (or force=true). Prompt + CORE-GAPS document the
four usability cores; handoff re-observe guidance tightened.
Prefer natural assistant text for greetings/no-tools; summarize progress
before max-rounds Blocked; CLI recovery hints for run/agent; GROKBOY_MAX_ROUNDS.