@internal Display metadata for this message's tool_use blocks, keyed by block id. display_name is the MCP server's `tool.annotations.title` when provided, otherwise a readable transform of the wire name; server_display_name is the MCP server's own display name; icon_url is the MCP server's directory icon URL (claude.ai connectors only). Omitted for blocks whose display label equals the wire name (built-in tools). Wrapper-level sibling — never inside `message.content` — so it is not replayed to the model.