Long-Horizon State Tracking in LLMs: Executing MD5 through a Deep Sequence of Dependent Tool Calls
Gpt-oss-120b, a mixture-of-experts model with only $\sim$5.5B active parameters per token, carries the full state across all calls and returns the correct digest on a majority of completed runs, and localizes the residual failures by origin, separating state-carrying from arithmetic and from serving.