Overview
Compression can omit details that later matter. The summary should therefore point to authoritative files rather than pretend to replace them. Instructions also become stale. Commands change, directories move, tools are replaced, and preferences evolve.
Long instruction files create their own context burden. Contradictory rules can be worse than missing rules because the agent must guess which one has priority. Periodic review should remove duplicates, obsolete facts, and conflicts.
A project summary is not a substitute for observation. It is a routing layer that tells the agent what the project contains and where to inspect when a task requires exact information.