List external conversation messages

Use to read what the guest and assistant said, including message types and stored media context. Discover conversationId with list_conversations. Use each stored messageId for get_message_status, get_conversation_attachment or, for an AI assistant answer, get_conversation_answer_trace. Action results are separate: use list_action_executions filtered by conversationId. Requires conversations:read. Returns customer-facing user and assistant messages in newest-first order, including shared locations, contacts, reactions, media, rendered cards/actions, referrals and delivery details when present. Pass nextCursor as cursor for older messages with the same conversationId; stop when hasMore is false. Internal system/tool activity is excluded. Use conversation.needsReply from metadata as the operator-action signal. Unknown delivery status is not delivery proof.