SamplingMessage.contentBlocks

All content blocks of the message. The spec models a sampling message's content as a single block OR an array of blocks (SamplingMessageContentBlock | SamplingMessageContentBlock[], schema.ts). A tool-loop follow-up request carries multiple blocks: an assistant message with several tool_use blocks and a user message with several tool_result blocks. This field holds every block so none is dropped. For the common single-block message, use the content accessor.

struct SamplingMessage
Content[] contentBlocks;