Closed-loop synthesis efficiently trains language models to use external tools
The authors replace conventional generate-then-filter data synthesis with a loop that generates, verifies, and refines examples at multiple stages. A 4B-parameter model trained on 11K ToolLoop examples reached 86.40% accuracy on the Berkeley Function Calling Leaderboard and generalized to ACEBench with substantially less training data than the cited baseline.
10 Sept 2026