Under the hoodTier: how much it should matter to you
1Useful: my rating, 1 to 5
2Signal: worth watching, 1 to 5
Tool CallsArea: what it touches
Internal ChangesKind: in v2.1.296,
Internal ChangesSection of the release
What
Each tool Claude Code offers the model is described by a tool definition, which can carry optional fields that not every API accepts. citations is now one of those fields:
The list of optional tool fields, previously strict and eager_input_streaming, now also includes citations.
When a capability check says the field is not supported, the cleanup step now removes citations in the same way it already removed eager_input_streaming.
The function that strips API-only fields from tool definitions (eager_input_streaming, defer_loading, strict) now strips citations as well, so tool definitions carrying it are cleaned before they are sent.
Why
In practice, tool definitions that include citations are no longer sent as-is to providers or endpoints that the capability check says do not support it.
