Sub-agents now run tool calls simultaneously in v4.1.20

The official source reports this update: v4.1.20. Changed Sub-agents spawned in the same step now run their tool calls at the same time rather than one after another. Tools that must run in order still do, and the parent still waits for every result before its next turn. Models that advertise a large output limit now get a bigger default output budget — 30% of the limit rather than a flat 32,000 tokens, whichever is larger. Nothing changes for models under roughly 107k output tokens; longer responses can mean higher per-turn cost and latency. Refreshed the model catalog: 203 to 209 providers and 6,079 to 6,237 models.