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 v2.1.273 ·

Tool-preset exclusion syntax (!ToolName) gated by a new killswitch

Tool presets can now exclude specific tools with a '!ToolName' syntax

TierUse it nowhow much it should matter to you
Useful4my rating, 1 to 5
Signal3worth watching, 1 to 5
AreaTool Presetswhat it touches
KindNew Featuresin v2.1.273,
Use it now Notable

Tool presets can now exclude specific tools with a '!ToolName' syntax

What

When configuring a tool preset (a named list of tools), you can now exclude a specific tool by prefixing its name with !, for example !Bash, and it will be filtered out of the resolved tool set.

Why

This lets you build a tool preset by starting from a broader set and excluding specific tools you don't want, rather than having to list every tool you do want.

Read from
Feature flag
tengu_tools_exclusion_killswitch Not enough to say

Nothing here resolved what this flag was doing on this version, so nothing here should be read as on or off.

This account: no value returned · anonymous baseline: no value returned · compiled default in v2.1.273: off

These values were read against a different version of Claude Code, so treat them as the nearest reading available instead of one taken on this release.

Read once, for one account on one subscription tier, against v2.1.273. It isn't a statement about your account. What a flag value here can and cannot tell you

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 doubtThe finding notes this exclusion parsing can be disabled by a killswitch flag, but whether it is active for this site's account is not…
The name it cites is new in this buildNew in this build: tengu_tools_exclusion_killswitch

See this entry in the whole of v2.1.273 →