field-notes
Claude's token-efficient tools header has no page left to check (2026)
Anthropic tells you to remove token-efficient-tools-2025-02-19 because it has no effect. The page that defined it now 307s to a migration guide index that mentions neither the feature nor beta headers. Measured October 2026: 0 occurrences across a 760-URL documentation index, and the whole surviving description is one sentence on one of four model migration guides.
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