Type alias AiGatewayMetadataCaptureItem

An item Metadata-only capture can add to LLM Observability spans. Each is structure or a number, never conversation text. tool_usage adds tool call and result counts; tool_output_size adds estimated tool output tokens, total and average; tool_names adds each tool call and result with its name, ID and type; conversation_shape adds every message with its role and no text; input_size_by_role adds estimated input tokens per role; available_tools adds the names of the tools the request offered; generation_settings adds numeric and enumerated settings such as temperature and the finish reason.