IBM Research Reports Learned Memory Tops τ²-Bench Service Benchmark

In an October 20, 2026 post on Hugging Face, IBM Research reported that guidelines learned automatically from an agent's own training runs and appended to its system prompt lifted a stock GPT-4.1 customer-service agent to 67.5% Pass^4 on τ²-bench's retail domain, above every retail entry in the team's October 12, 2026 leaderboard snapshot. The result comes from ALTK-Evolve, the lab's method for building what the authors describe as a learned playbook. The method analyzes an agent's attempts on…

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