Say where the request size limit actually applies

Say where the request size limit actually applies The API reference put the 65,536-byte cap on the body field. The service checks Content-Length before parsing the JSON, so the cap covers the whole encoded request: a body of exactly that size returns 400 once the surrounding object is counted, which is the boundary a client reading this page would have trusted. Co-Authored-By: Claude Opus 5 (1M context) Claude-Session: https://claude.ai/code/session_01XmzqahsmAXBn5wJab92jP2