OpenAI GPT-5.2 (none)57.2% sierra-tau-bench-public.s3.us-west-2.amazonaws.com for GPT-5.2 (none) on τ³-bench τ³ — Telecom (opens in a new tab) Archived copy (opens in a new tab) Task success rate Reported May 26, 2026 Evaluated May 26, 2026 Benchmark leaderboard Sierra Independent Sierra Research Record for GPT-5.2 on τ³-bench τ³ — Telecom 10012 Mistral AI Mistral Medium 3.5 (high)91.4% huggingface.co for Mistral Medium 3.5 (high) on τ³-bench τ³ — Telecom (opens in a new tab) Task success rate Reported May 22, 2026 Model card Mistral AI Self-reported Record for Mistral Medium 3.5 on τ³-bench τ³ — Telecom 90005 OpenAI GPT-5.2 (high)89.7% sierra-tau-bench-public.s3.us-west-2.amazonaws.com for GPT-5.2 (high) on τ³-bench τ³ — Telecom (opens in a new tab) Archived copy (opens in a new tab) Task success rate Reported May 5, 2026 Evaluated May 5, 2026 Benchmark leaderboard Sierra Independent Sierra Research Record for GPT-5.2 on τ³-bench τ³ — Telecom 10012 Anthropic Claude Opus 4.5 (high)92.3% sierra-tau-bench-public.s3.us-west-2.amazonaws.com for Claude Opus 4.5 (high) on τ³-bench τ³ — Telecom (opens in a new tab) Archived copy (opens in a new tab) Task success rate Reported May 5, 2026 Evaluated May 5, 2026 Benchmark leaderboard Sierra Independent Sierra Research Record for Claude Opus 4.5 on τ³-bench τ³ — Telecom 20007 Alibaba (Tongyi) Qwen3.5-397B-A17B (enabled)97.8% sierra-tau-bench-public.s3.us-west-2.amazonaws.com for Qwen3.5-397B-A17B (enabled) on τ³-bench τ³ — Telecom (opens in a new tab) Archived copy (opens in a new tab) Task success rate Reported March 2, 2026 Evaluated February 27, 2026 Benchmark leaderboard Sierra Independent Sierra Research Record for Qwen3.5-397B-A17B on τ³-bench τ³ — Telecom 130003 Z.ai GLM-5 (enabled)86.8% sierra-tau-bench-public.s3.us-west-2.amazonaws.com for GLM-5 (enabled) on τ³-bench τ³ — Telecom (opens in a new tab) Archived copy (opens in a new tab) Task success rate Reported March 2, 2026 Evaluated February 27, 2026 Benchmark leaderboard Sierra Independent Sierra Research Record for GLM-5 on τ³-bench τ³ — Telecom 150002 Google (DeepMind) Gemini 3 Pro (high)91.0% sierra-tau-bench-public.s3.us-west-2.amazonaws.com for Gemini 3 Pro (high) on τ³-bench τ³ — Telecom (opens in a new tab) Archived copy (opens in a new tab) Task success rate Reported March 2, 2026 Evaluated March 2, 2026 Benchmark leaderboard Sierra Independent Sierra Research Record for Gemini 3 Pro on τ³-bench τ³ — Telecom 30008 Google (DeepMind) Gemini 3 Flash (high)91.2% sierra-tau-bench-public.s3.us-west-2.amazonaws.com for Gemini 3 Flash (high) on τ³-bench τ³ — Telecom (opens in a new tab) Archived copy (opens in a new tab) Task success rate Reported March 2, 2026 Evaluated March 2, 2026 Benchmark leaderboard Sierra Independent Sierra Research Record for Gemini 3 Flash on τ³-bench τ³ — Telecom 30009 Anthropic Claude Sonnet 4.5 (enabled)84.9% sierra-tau-bench-public.s3.us-west-2.amazonaws.com for Claude Sonnet 4.5 (enabled) on τ³-bench τ³ — Telecom (opens in a new tab) Archived copy (opens in a new tab) Task success rate Reported February 26, 2026 Evaluated February 24, 2026 Benchmark leaderboard Sierra Independent Sierra Research Record for Claude Sonnet 4.5 on τ³-bench τ³ — Telecom 20005