Researchers released Model Discovery Agent, a system that lets a large language model propose mechanistic structures while sequential Monte Carlo, simulation-based inference and value-of-information design choose the next experiments. On ForceBench, ChemBench and a new NeuronBench electrophysiology suite, MDA claims state-of-the-art data-efficient discovery and interventional forecasts when the true mechanism starts outside the current hypothesis class. A predictive check flags misspecification, then the proposer expands the model space and designed interventions identify parameters. That matters for labs that cannot afford brute-force data collection. The caveat is that the August 11 arXiv report still needs independent reproduction.