Opus 4.8 Reported to Have Regressed in Tool Calling
mitsuhiko · x · 2026-07-05
Prominent developer Armin Ronacher (mitsuhiko) found that the latest Opus 4.8 and Sonnet fail when calling Pi's edit tool, an issue absent in older versions. He had previously suspected that the new Opus was degrading on tasks outside its training distribution; he has now gathered evidence and written an analysis on this capability regression.
More from Models
- Nanbeige4.3-33B benchmarked: 59 tok/s single stream, ~1,060 tok/s across 64 concurrent runs — MaziyarPanahi · 2026-10-26
- Only 2 of 25 full ChatGPT rewrites flagged 100% AI by detectors — paulnovosad · 2026-10-26
- Qwen 4 Reportedly Spotted in the Arena, Hints at Alibaba's Next-Gen Model Testing — AIFlow_ML · 2026-10-26
- Nathan Lambert's first open models lecture: distillation, risks and the ecosystem explained — natolambert · 2026-10-26
- Nanbeige 4.3-33B flops real-world test: zero compilable output vs Qwen — julianharris · 2026-10-26
- Claude's safety classifier blocks SS7 defense research, pushing a security dev to an abliterated GLM — l4rz · 2026-10-26