Prompts Allocate Agent Work: Four Shapes of Waste Across 4,644 Runs
With task, model, tools, and grading held fixed, only the user's wording changed. Asking to compare several approaches raised reasoning 2.4 to 7.4x, elaborating about 3 branches that were then discarded. Demanding certainty turned caution into action, costing 18.25x at the most expensive level with 15 tool calls against 6. Success did not improve. Four shapes of waste draw on different cost carriers, so they need different controls. Includes independent checks on the paper itself.