Instead of relying on lossy LLM-based summarization, architect agent memory into three tiers: an ephemeral scratchpad for immediate tasks, a deterministic state machine for history (e.g., Redis), and a semantic anchor (e.g., vector store) for global knowledge lookup.
Long-running AI agents don't fail because the model is unintelligent. They fail because default memory management, like unmonitored append-only context windows, corrupts their state. This is a software engineering problem that requires an architectural solution, not better prompting or model tuning.
Simply stuffing all historical data into a large context window is counterproductive. The model's attention gets diluted by repetitive tool logs and intermediate data, making it struggle to find original instructions. This "signal versus noise" problem leads to hallucinations and degraded performance.