Claude Fable 5.2 review finds strong capabilities but persistent gaps
One Useful Thing author Ethan Mollick used Claude Fable 5.2 extensively before its public launch and described it as “very impressive,” following the already excellent Claude Opus 5.5. In tests involving code, video creation, research and other difficult intellectual tasks, he called the model “almost” AGI, or “Jagged AGI.” He also said it still falls behind human capability in important areas and does not reliably recognize when its own work is inadequate, often requiring human oversight to correct problems such as excessive length or repetition.
The first-hand assessment documents Fable 5.2's ability to handle complex, varied projects while showing that its quality control and expert judgment remain inconsistent. The author says human monitoring often made the difference between less impressive and more impressive results.
Before getting started, I wanted to thank my readers for making my new book, Co-Existence, a New York Times bestseller two weeks in a row. If you haven’t read it, you can get a copy here.
I have had the chance to use the new Claude Fable 5.2 quite a bit before its public launch1, and it is very impressive, following on the already excellent Opus 5.5. AI has gotten so good, in fact, that it is worth asking if Anthropic’s newest models (and the inevitable competing models OpenAI and Google will soon release) cross the boundary into being an Artificial General Intelligence? AGI is a much-debated term with a lot of potential definitions. For this post, I’ll go with: “an AI as good as most human experts at most intellectual tasks you can do with a computer.” This explicitly excludes a lot of human work, including interacting with the physical world and other people, as well as most actual jobs, where “using a computer” is just one task among many. Still, even with these caveats, building a limited form of AGI has long been the goal of AI developers.