If you've ever worked with an LLM-powered agent long enough for a session to grow, you've probably felt it. Instructions that worked perfectly in a fresh conversation get quietly ignored 15 turns in. The agent starts referencing things it shouldn't. Retrieved snippets that were relevant three queries ago somehow bleed into an answer to a completely different question. Everything looks fine — no errors, no crashes — but the quality of reasoning has visibly degraded. That set of degradations ...