Under the hoodTier: how much it should matter to you
1Useful: my rating, 1 to 5
1Signal: worth watching, 1 to 5
Tool ValidationArea: what it touches
Internal ChangesKind: in v2.1.277,
Internal ChangesSection of the release
What
When Claude Code fails to parse a tool's input as JSON, the internal telemetry event tengu_tool_input_json_parse_fail now records an isMcp field noting whether the tool came from an MCP server (a way of connecting external tools to Claude Code). Related error logging for schema-normalization failures (checked with a library called Zod) now includes the tool's display name, the list of specific Zod issue codes, and the length of the error message, instead of a single flattened error string.
Why
This gives more structured detail for diagnosing why a tool call's input failed to parse, without changing what happens for the user in the moment.
