Q4_K_M is fine for chat and a trap for agents. Here is math mathing.

In three linesQ4_K_M quantization is suitable for chat but problematic for agentic loops. At ~3% error rate per call, a 30-step loop achieves 40% success (vs 91% at Q6). Silent failures (valid format, wrong content) propagate downstream undetected inline.

Summary generated by Claude — human-verified