diff --git a/.github/scripts/tests/templates/summary.html b/.github/scripts/tests/templates/summary.html
index 65e7a02d514b..e01e945f41db 100644
--- a/.github/scripts/tests/templates/summary.html
+++ b/.github/scripts/tests/templates/summary.html
@@ -491,11 +491,33 @@
 
     // Configuration constants
     const MAX_URL_LENGTH = 8000; // GitHub URL limit is 8201, stay under 8000 to be safe
-    const LOG_ENTRY_ESTIMATE = 150; // Estimated characters per log entry
-    const MIN_REMAINING_SPACE = 100; // Minimum space needed for log section
-    const ERROR_BUFFER_SPACE = 50; // Buffer space when adding error details
+    const GITHUB_ISSUE_BASE_URL = "https://github.com/ydb-platform/ydb/issues/new"; // Base URL for GitHub issues
 
     // Utility functions
+    function buildGitHubIssueUrl(title, body, labels) {
+        return GITHUB_ISSUE_BASE_URL + "?title=" + title + "&body=" + body + "&labels=" + labels + "&type=Bug";
+    }
+
+    // Show tooltip stub to avoid runtime errors (visual feedback provided by icon swap)
+    function showCopiedTooltip() {}
+
+    // Safe percent-encoded truncation helpers
+    function isDecodable(s) {
+        try { decodeURIComponent(s); return true; } catch (e) { return false; }
+    }
+
+    function safeTruncateEncoded(encoded, maxLen) {
+        if (encoded.length <= maxLen) return encoded;
+        let cut = encoded.slice(0, maxLen);
+        // Remove incomplete % sequence at the tail
+        cut = cut.replace(/%(?:[0-9A-Fa-f]{0,2})$/, '');
+        while (cut && !isDecodable(cut)) {
+            if (/%[0-9A-Fa-f]{2}$/.test(cut)) cut = cut.slice(0, -3);
+            else cut = cut.slice(0, -1);
+        }
+        return cut;
+    }
+
     function parseTestName(full_name) {
         const trimmed = full_name.trim();
         let pieces;
@@ -611,46 +633,47 @@
         return body;
     }
 
-    function addOptionalContent(baseBody, logUrls, errorText, remainingSpace) {
+    function buildBodyWithLengthLimit(baseBody, logUrls, errorText, title, labels, maxUrlLength) {
         let body = baseBody;
-        let availableSpace = remainingSpace;
         
-        // Add logs if space allows
-        if (logUrls && Object.keys(logUrls).length > 0 && availableSpace > MIN_REMAINING_SPACE) {
+        // Add logs first
+        if (logUrls && Object.keys(logUrls).length > 0) {
             let logsSection = "**Logs:**%0A";
-            let logCount = 0;
-            const maxLogs = Math.min(Object.keys(logUrls).length, Math.floor(availableSpace / LOG_ENTRY_ESTIMATE));
-            
             for (const [logName, logUrl] of Object.entries(logUrls)) {
-                if (logCount >= maxLogs) break;
-                const logEntry = "- [" + encodeURIComponent(logName) + "](" + encodeURIComponent(logUrl) + ")%0A";
-                if (logsSection.length + logEntry.length < availableSpace - ERROR_BUFFER_SPACE) {
-                    logsSection += logEntry;
-                    logCount++;
-                } else {
-                    break;
-                }
-            }
-            
-            if (Object.keys(logUrls).length > logCount) {
-                logsSection += "- (and " + (Object.keys(logUrls).length - logCount) + " more logs in report)%0A";
+                logsSection += "- [" + encodeURIComponent(logName) + "](" + encodeURIComponent(logUrl) + ")%0A";
             }
             logsSection += "%0A";
-            
             body += logsSection;
-            availableSpace -= logsSection.length;
         }
         
-        // Add error details if space allows
-        if (errorText && errorText.trim() !== "" && availableSpace > ERROR_BUFFER_SPACE) {
-            const maxErrorLength = Math.min(errorText.trim().length, availableSpace - ERROR_BUFFER_SPACE);
-            const errorToShow = errorText.trim().substring(0, maxErrorLength);
-            let errorSection = "**Error Summary:**%0A```%0A" + encodeURIComponent(errorToShow);
-            if (errorText.trim().length > maxErrorLength) {
-                errorSection += "... (see full error in test report)";
+        // Try to add error text, checking actual URL length
+        if (errorText && errorText.trim() !== "") {
+            const errorPrefix = "**Error Summary:**%0A```%0A";
+            const errorSuffix = "%0A```%0A%0A";
+            const truncationMsg = "%0A<TRUNCATED>";
+            
+            const fullErrorText = errorText.trim();
+            const encodedFullError = encodeURIComponent(fullErrorText);
+
+            // Compute minimal overhead URL length (without error content)
+            const minimalSection = errorPrefix + errorSuffix;
+            const minimalUrl = buildGitHubIssueUrl(title, body + minimalSection, labels);
+            if (minimalUrl.length > maxUrlLength) {
+                // Can't include error section at all
+            } else {
+                const allowedDelta = maxUrlLength - minimalUrl.length;
+                if (encodedFullError.length <= allowedDelta) {
+                    body += errorPrefix + encodedFullError + errorSuffix;
+                } else {
+                    const allowedForEncoded = allowedDelta - truncationMsg.length;
+                    if (allowedForEncoded > 0) {
+                        const truncatedEncoded = safeTruncateEncoded(encodedFullError, allowedForEncoded);
+                        if (truncatedEncoded) {
+                            body += errorPrefix + truncatedEncoded + truncationMsg + errorSuffix;
+                        }
+                    }
+                }
             }
-            errorSection += "%0A```%0A%0A";
-            body += errorSection;
         }
         
         return body;
@@ -691,15 +714,11 @@
         // Build labels
         const labels = buildLabels(actualIssueType, buildPreset, ownerAreaLabel);
         
-        // Calculate base URL length
-        const baseUrl = "https://github.com/ydb-platform/ydb/issues/new?title=" + title + "&body=" + body + "&labels=" + labels + "&type=Bug";
-        const remainingSpace = MAX_URL_LENGTH - baseUrl.length;
-        
-        // Add optional content based on available space
-        const finalBody = addOptionalContent(body, logUrls, errorText, remainingSpace);
+        // Build body with exact length limit checking
+        const finalBody = buildBodyWithLengthLimit(body, logUrls, errorText, title, labels, MAX_URL_LENGTH);
         
         // Create final URL and open
-        const finalUrl = "https://github.com/ydb-platform/ydb/issues/new?title=" + title + "&body=" + finalBody + "&labels=" + labels + "&type=Bug";
+        const finalUrl = buildGitHubIssueUrl(title, finalBody, labels);
         window.open(finalUrl, '_blank');
     }