final int summaryMaxChars) {
        switch (mode) {
        case "full":
            return msg.getContent();
        case "smart_summary":
            return buildSmartSummaryContent(msg, summaryMaxChars);
        case "source_titles":
            return buildSourceTitlesContent(msg, summaryMaxChars);
        case "source_titles_and_urls":
            return buildSourceTitlesAndUrlsContent(msg);