One thing I didn't see anywhere here, except your mention about pulling in large number of skills, is that the token consumption is significantly higher for users with many agents, skills, and MCPs installed, and many are mere ghosts. The 5m TTL from #46829 compounds the effect: in my case, I found ~20k tokens of ghost context I hadn't intentionally opened. Each idle period after 5m wastes that as a full cache miss.

Boris, would you please confirm on-record: is the current cache TTL for the main agent context 1h or 5m? Issue #46829 was closed as "not planned".