Claude Code v2.1.311 · 26 Oct 2026
Warnings about unknown tools in permission rules reworked behind the scenes
Startup checks of permission rules were reorganised; the warning for a rule that names no known tool reads the same
Under the hood Tier: how much it should matter to you
1 Useful: my rating, 1 to 5
1 Signal: worth watching, 1 to 5
Permissions Area: what it touches
Internal Changes Kind: in v2.1.311, 26 Oct 26
Internal Changes Section of the release
Unclear It is not clear whether the reorganisation changes which warnings appear or when.
What
At startup Claude Code checks your permission rules, the rules that allow or deny tools, and warns about problems such as a rule that "matches no known tool - check for typos." This check has been reorganised so that it also returns security warnings. The warnings still point to --allowed-tools , --disallowed-tools and --settings , and the wording looks unchanged.
Why
In practice the warnings you see should look the same as before.
How sure we are
Something disagrees Something we can check disagrees with this entry, or the writer said they could not settle it.
The writer flagged doubt It is not clear whether the reorganisation changes which warnings appear or when.
See this entry in the whole of v2.1.311 →
26 Oct 2026 · 425 entries, this one is #390.
Use it now29 You'll notice242 Nothing to try yet10 Under the hood144
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Names in this entry
cli --allowed-tools Tools that execute without prompting for permission, apart from reads from network paths . See permission rule syntax for pattern matching. To restrict which tools are available, use --tools instead. If you name one of the task-tracking tools here, Claude Code also opts the session in
cli --disallowed-tools Deny rules. A bare tool name removes the matching tools from Claude's context: "Edit" removes Edit, "" removes every tool, and "mcp__" removes every MCP tool. A scoped rule such as Bash(rm *) leaves the tool available and denies only calls that match as written . A rule naming EndConversation can't remove it while any other tool remains
cli --settings Path to a settings JSON file or an inline JSON string. Values you set here override the same keys in your settings.json files for this session. Keys you omit keep their file-based values. The file must be a regular file no larger than 2 MiB. See settings precedence
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What's wrong with this entry?
Hard to understand Too vague Looks wrong Not relevant to me Too long Missing the detail I wanted Duplicate of another card
Clear Learned something new I can act on this Good catch
Related
Other releases about the same thing. Found by shared names or similar wording; neither means one caused the other.
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Permission mode choice takes account of settings that are never forwarded
Under the hood Permissions
In v2.1.311 Internal Changes release-page order
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Security warnings are now stored as text entries and matched by their text
Under the hood Permissions