Sweep 19 Sep 2026 · 02:36Z Build v2.1.278 500 read Stable v2.1.267 Latest v2.1.278 Next v2.1.278 Feeds RSS JSON llms.txt Unofficial
Claude Code v2.1.269 ·

Undeclared MCP/tool cleanup at compaction

Claude Code can now drop unused MCP tools from a session's declared-tools list when compacting the conversation

TierYou'll noticehow much it should matter to you
Useful2my rating, 1 to 5
Signal2worth watching, 1 to 5
AreaCompactionwhat it touches
KindImprovementsin v2.1.269,
You'll notice

Claude Code can now drop unused MCP tools from a session's declared-tools list when compacting the conversation

What

When a long conversation is compacted (summarized to save space), a new internal helper can now strip tools that are no longer needed from the session's list of declared tools (the tools, including those from MCP servers, that the session knows about). It also records how many tools were dropped this way.

Why

This is internal housekeeping: keeping the declared-tools list trimmed at compaction time can reduce clutter and unnecessary bookkeeping in long sessions.

How sure we are
Something disagreesSomething we can check disagrees with this entry, or the writer said they could not settle it.
The writer flagged doubtNothing has been read yet about whether this cleanup is switched on for any account, so its practical effect is unknown.

See this entry in the whole of v2.1.269 →