Under the hood
Checking for newly available tools mid-session now uses a faster cached check first
What
The internal logic that decides whether to compute and announce a deferred_tools_delta (a signal that new tools have become available partway through a session) now first tries a quick cached check using toolPoolRefreshes and aheadOfRequest. It only falls back to the previous, more expensive full set of eligibility checks if that quick check doesn't resolve the question.
Why
This is a performance change: it avoids redoing full eligibility computation on every check, which should make detecting newly available tools mid-session cheaper without changing what tools end up available.