You'll noticeTier: how much it should matter to you
1Useful: my rating, 1 to 5
1Signal: worth watching, 1 to 5
Tool SearchArea: what it touches
ImprovementsKind: in v2.1.318,
ImprovementsSection of the release
What
Some tools are deferred, meaning their full description is left out of Claude's prompt until they are needed. A tool's input schema is the description of what inputs it accepts. If Claude calls a deferred tool whose schema was not in the prompt, the error now adds "This tool's input schema was not in your prompt when you called it." It then does one of two things:
shows the schema
tells Claude to load the tool through the tool-search tool using select:<name>
The hint is left out if an earlier result already ended with the same instruction.
Why
This should mean fewer repeated failed calls to deferred tools.
