Under the hood
Internal tool-pool cache now also depends on WaitForMcpServers usage and a REPL primitive grant
What
Claude Code's internal cache of which tools are available (the "tool pool") now also takes into account two more factors when deciding whether to reuse a cached result: whether the host has declared it uses the WaitForMcpServers tool, and a "REPL primitive grant" derived from the main agent. Previously the cache only tracked the set of tools and allowed subagent types.
Why
This is an internal correctness fix: without tracking these inputs, the tool pool could theoretically serve a stale cached result when either of these factors changed. It shouldn't be noticeable to users beyond more accurate tool availability.