Context rot, compaction, clear vs. summarise

Long-running agents accumulate context that degrades their performance — earlier
information receives less attention, and irrelevant material pollutes reasoning.
Students learn the practical countermeasures: when to compact (summarise history
and continue) versus when to clear entirely and start fresh, and how to recognise
the symptoms of a degraded context (repeating corrected mistakes, referencing
irrelevant files, contradicting established constraints).