Anthropic Launches Advisor Tool: Pair Opus as Strategic Advisor with Sonnet/Haiku as Executor

Anthropic·high signal

Anthropic released the advisor tool in beta (anthropic-beta: advisor-tool-2026-03-01), letting developers pair Opus as a strategic advisor with Sonnet or Haiku as the task executor. In benchmarks, Sonnet+Opus advisor gained +2.7pp on SWE-bench Multilingual while cutting cost per agentic task by 11.9%; Haiku+Opus advisor scored 41.2% on BrowseComp — more than double Haiku's solo 19.7%. The pattern: executor runs end-to-end, consults Opus only at decision points it can't resolve alone.