The lost-in-the-middle effect is not theory anymore. You can see it in daily agent sessions.
Important rules buried halfway down a long prompt get skipped. Then people blame the model. Most times, this is placement, not intelligence.
Where instructions should live
Put non-negotiables at the top: coding rules, forbidden paths, test commands. Repeat critical items near the end if needed.
Middle sections should hold disposable detail. If that part gets weaker attention, nothing critical breaks.
My prompt layout
- Top: constraints and completion bar.
- Middle: context notes, references, optional detail.
- Bottom: current task and explicit next command.
That shape follows how attention behaves across a long context window.
When drift starts
If output quality drops, I do not add more text. I reset and reload. Fresh context beats rescue prompting.
This is why compaction often disappoints. You stay near the noisy zone and hope for miracles.
One practical rule
If a rule matters, it should appear in a durable file and in the active task prompt. Redundancy on purpose.
That one habit cut repeat mistakes across my sessions more than any model upgrade.