You can actually tell from the very first real sentence in the README:

> Efficiency is a 162-run controlled benchmark (same agent, same file tools, only the context differs).

It's so bad that I can tell it's Claude, specifically Opus 4.8/5.0, from the first 6 words.

Opus 5 is very paranoid on giving proofs for every thing it claimed. so I let it keep this one line.