When the Agent loops for fifteen turns within a step without completing it, the Harness sends a three-part notice: the first part states the count and names the step; the second part provides the evidence gap; the third part offers the exit of "report failure" and closes with "do not keep exploring". Five turns later comes a more blunt warning, requiring the Agent to call the step completion tool on the next turn and threatening that continued exploration will cause that Agent to be terminated.