> Agent Lineage Evolution (ALE) is a novel framework that addresses the dual challenge of LLM agent degradation and manual prompt engineering bottlenecks. As LLMs inevitably degrade over extended usage, requiring frequent context restarts, current approaches force humans to manually re-engineer prompts with learned optimizations for each restart. ALE eliminates this scaling limitation by enabling agents to automatically generate successor prompts with embedded behavioral knowledge, transforming inevitable degradation cycles into opportunities for automated prompt evolution.