Under the hoodTier: how much it should matter to you
2Useful: my rating, 1 to 5
3Signal: worth watching, 1 to 5
MCPArea: what it touches
Internal ChangesKind: in v2.1.257,
Internal ChangesSection of the release
Tracking of MCP tools declared with defer_loading now records whether a deferred tool's entry differs from what was actually sent when referenced, reporting via the mcp_kept_deferred_tools telemetry event, including a dedicated failure case for this bookkeeping.
Read from
Names in the bundledefer_loading
Since it was published
The entry above is what we published on the day. These lines were added later, as Anthropic's own pages caught up, and they sit beside the original rather than replacing it.
Confirmed sinceAnthropic's documentation has since written up defer_loading, on Batches.- `defer_loading: optional boolean or null`api/messages/batchessee the edit
How sure we are
One source agreesOne thing we can check says the same as this entry.
Anthropic's documentation agreesAnthropic's documentation has since written up defer_loading, on Batches.
