The warning added one commit earlier echoed the rejected value. That is the
same leak class as the `servers/show` fix: `_meta` now carries arbitrary JSON,
so an invalid `progressToken` can be an object holding credentials — and this
logger is persisted by real clients (`clients/tui/src/logger.ts` writes it to
`~/.mcp-inspector/auth.log` via `pino.destination`, append mode).
Log `{ received: describeJsonType(value) }` instead — "object", "array",
"number". That is what makes the warning actionable; the value itself only
leaks.
Test asserts the record is exactly `{ received: "object" }` and that the
planted secret appears nowhere in the captured calls.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0177mPHAdECD18nLLCTwR5rh
Signed-off-by: cliffhall <cliff@futurescale.com>