For tool-heavy agents, a recency window plus a running summary beats a retriever (no external store needed)

arXiv:2606.10209·high signal

'Less Context, Better Agents' (arXiv:2606.10209) shows that for long-horizon, tool-using agents drowning in verbose tool responses, a lightweight recency window combined with a compact running summary is sufficient to complete tasks reliably — no external vector store or retriever required. This is a useful counter to the reflex of bolting RAG onto every agent: the simplest context-management scheme often wins on tool-heavy workflows. Before you stand up a retrieval layer, try recency+summary and measure whether it actually loses anything.