Creates an assistant message object, representing the assistant's response.

This is the tool call message, which must come immediately before the tool_msg/3 message with the same tool_call_id (id).

Creates a system message object, used to define the assistant's behavior for the conversation.

This is the tool outputs message, which must come immediately after the assistant_tool_msg/3 message with the same tool_call_id (id).

Creates a user message object, representing the user's input prompt.