Does Quantization Break Tool-Calling? I Measured It on a 4GB Laptop GPU (BFCL, 3 Seeds, Bootstrap 95% CI)

"Is Q4 safe for tool-calling?" gets asked constantly in local-LLM circles, and the answers are almost always anecdotal — a few hundred agent-hours on one model, extrapolated to everything. I wanted a benchmark where every degradation claim comes from bootstrapping the paired per-seed delta itself , not from eyeballing whether two confidence intervals happen to overlap. So I built one: QuantCall . No cloud GPUs involved — everything below ran on my own hardware, an RTX 3050 Laptop with 4096 MiB…