We used OpenClaw to run these experiments so that our scaffold was agnostic to the model provider. We conducted dry-run experiments with models from OpenAI and Anthropic before settling on Opus 4.8 as the best-performing model. In response to concerns that our results might be principally explained by a limitation in our scaffold, we repeated our experiment on one paper using GPT-5.6 Sol and Codex, its native scaffold, with the same time and API budgets. The results of this experiment were similar to our OpenClaw/Opus 4.8 experiments. This makes us more confident that our results are not simply artifacts of a scaffold deficiency; this run reproduced nearly every single one of our identified failure modes

The agent required three interventions during the run. First, we needed to modify the scaffold to resolve a bug in the OpenClaw harness that affected Anthropic reasoning models. Second, we gave the agents a 24-hour deadline extension; at the time of the original deadline, the agents had submitted drafts with a completion report indicating that their self-review was a "Weak Reject" and outlining the next steps they would take if given additional time.

I'm fairly sure Fable 5.1 could have designed a better experiment than the authors here, but hey.