{"version":"2.1.321","anchor":"tool-pool-change-logged-at-cache-expiry-new-telemetry-and-t","canonical_anchor":"tool-pool-change-logged-at-cache-expiry-new-telemetry-and-t","heading":"Claude Code records tool list changes when its cache expires","tier":"internal","area":"Elsewhere","scope":"individual","heads_up":false,"url":"https:\/\/changelogs.core-directive.com\/v\/2.1.321\/e\/tool-pool-change-logged-at-cache-expiry-new-telemetry-and-t","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.321","markdown":"### Claude Code records tool list changes when its cache expires\n\nClaude Code now logs which tool was added or removed if the set of tools changed when its prompt cache expired\n\n**What**\n\nClaude 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.\n\n**Why**\n\nThis appears to be diagnostic data on tool list changes that stop the cache from being reused.\n\n- Area: Elsewhere\n- Tier: Under the hood\n- Useful: 1\/5\n- Signal: 2\/5\n- Scope: individual\n- Heads-up: no"}