Under the hoodTier: how much it should matter to you
1Useful: my rating, 1 to 5
2Signal: worth watching, 1 to 5
ElsewhereArea: what it touches
Internal ChangesKind: in v2.1.321,
Internal ChangesSection of the release
What
Claude Code now records when the set of tools available to Claude changed at the moment its prompt cache ran out. The prompt cache is a saved copy of the start of a conversation that makes later requests faster. Each record notes the tool's name and whether it was added or removed. Claude Code also reads a number from Anthropic's servers for this, kept within a fixed range and with a built-in fallback.
Why
This appears to be diagnostic data on tool list changes that stop the cache from being reused.
