Activity signals (tool calls like compress, grep, bash) were treated as
'progress' by the stagnation detector, resetting the stagnation counter
every cycle. This prevented MAX_STAGNATION_COUNT from being reached,
causing infinite continuation loops when models degrade to minimal
responses in long sessions (e.g. GLM-5.1 at ~100K tokens).
Stagnation now only tracks actual todo state changes: incomplete count
decrease, completed count increase, or todo snapshot change. Tool-level
activity no longer resets the stagnation counter.
Evgeny Zotov