a model is only half an agent system; the reasoning procedure around it is hand-written and its lessons never carry to the next task. Strategist is a meta-agent that evolves that second half: strategies are executable blueprints in a reusable library, retrieved, rewritten, tested on real samples, and banked for later tasks. Across 30 benchmarks it beats the strongest baseline on 24, matches its average accuracy (74.7% vs. 74.0%) at 39% lower inference cost, and its strategies transfer to unseen tasks and other models without further search.