The finding that self-generated skills provide negative benefit (-1.3pp) while curated skills give +16.2pp is the most interesting result here imo. Big discrepancy, but makes sense. Aligns with the thought that LLMs are better consumers of procedural knowledge than producers of it.

+4.5pp for software engineering is suspiciously low compared to +51.9pp for healthcare. I suspect this reflects that frontier models already have strong SWE priors from training data, so skills add less marginal value. If true, skills become most valuable precisely in the domains where models are weakest — which is where you'd actually want to deploy agents in production. That's encouraging.