Why reasoning models should not have to read everything

The AI industry has been expanding how much information an AI model can consume at once. In just a few years, context windows have grown from thousands of tokens to millions. Anthropic increased Claude’s context window from 9,000 to 100,000 tokens in May 2023, reaching 200,000 tokens by November 2023. Google’s Gemini 1.5 Pro reached one million tokens in February 2024, then two million by June 2024. By March 2026, Anthropic made the million-token window generally available across its Claude models, and thirteen or more hosted frontier models now offer one-million tokens or more. Reasoning syst