Command-line agents often report skipped work as success: Receipt reads kernel wait states and cuts false successes from 34 to 9
When LLM agents operate Web services from the command line, they assume every tool call returns within a bounded time with the requested action finished; but many commands ask a question first, and a harness that closes input can let a program return status 0 without doing the work, while an open input makes it wait until a time limit. Receipt keeps input open, reads from system calls what each process waits for, and returns that state to an unmodified agent; across 5 LLMs it lowers false successes from 34 under closed input to 9 and uses 24.4% fewer tokens than a plain terminal.