Overview
Many apparent reasoning failures are actually context-management failures. An agent that performed well at the beginning of a session may start making poor architectural decisions, forgetting constraints, or applying inconsistent edits after a long exploration and implementation sequence. The problem is not always the model's raw capability. It may be that the most demanding work is being attempted after the context has already become overloaded.
Task sizing therefore becomes an engineering control. A large feature should be divided into pieces that can each be explored, implemented, tested, and reviewed within a fresh smart-zone session. This is the same discipline that helps human developers avoid becoming overwhelmed by oversized tasks.