Optional_Extension point for implementations
The blocks of content that compose the user's message.
As a baseline, the Agent MUST support [ContentBlock::Text] and [ContentBlock::ResourceLink],
while other variants are optionally enabled via [PromptCapabilities].
The Client MUST adapt its interface according to [PromptCapabilities].
The client MAY include referenced pieces of context as either
[ContentBlock::Resource] or [ContentBlock::ResourceLink].
When available, [ContentBlock::Resource] is preferred
as it avoids extra round-trips and allows the message to include
pieces of context from sources the agent may not have access to.
The ID of the session to send this user message to
Request parameters for sending a user prompt to the agent.
Contains the user's message and any additional context.
See protocol docs: User Message