The two tooltip labels named the mechanism, not the thing on screen: "Max
output tokens" reads as a statistic, but the mask draws the window's tail held
back for the routed request's reply, and "Compaction headroom" said 余量 — slack
— where it is in fact reserved space. Say both as the regions they are:
Compaction Headroom 65.5k
LLM Output Reservation 256.0k
本次回复的输出预留在窗口末尾
Both English labels now share one Title Case so the three-row tooltip reads as
a set. The note lines keep their sentence form, so only labels changed.