Function-calling leader loses 14.0 points once unrequested destructive calls count
The Berkeley Function Calling Leaderboard checks only the final state, so models that ask before deleting get penalized; 260 of 734 reference turns act destructively without confirmation. CAREFUL-Bench replays runs and flags unrequested destructive calls, duplicate writes and surplus steps. Across 11 open models the ranking holds, but the leader loses 14.0 points and surplus steps use up to 28% of input tokens. The best model completes only six of 576 conversations needing confirmed destructive actions.