diff --git a/actions/setup/js/log_parser_bootstrap.cjs b/actions/setup/js/log_parser_bootstrap.cjs
index 172125c4f83..782da3d536a 100644
--- a/actions/setup/js/log_parser_bootstrap.cjs
+++ b/actions/setup/js/log_parser_bootstrap.cjs
@@ -1,7 +1,7 @@
 // @ts-check
 /// <reference types="@actions/github-script" />
 
-const { generatePlainTextSummary, generateCopilotCliStyleSummary, formatSafeOutputsPreview } = require("./log_parser_shared.cjs");
+const { generatePlainTextSummary, generateCopilotCliStyleSummary, wrapAgentLogInSection, formatSafeOutputsPreview } = require("./log_parser_shared.cjs");
 const { getErrorMessage } = require("./error_helpers.cjs");
 
 /**
@@ -157,8 +157,14 @@ async function runLogParser(options) {
           parserName,
         });
 
+        // Wrap the agent log in a details/summary section (open by default)
+        const wrappedAgentLog = wrapAgentLogInSection(copilotCliStyleMarkdown, {
+          parserName,
+          open: true,
+        });
+
         // Add safe outputs preview to step summary
-        let fullMarkdown = copilotCliStyleMarkdown;
+        let fullMarkdown = wrappedAgentLog;
         if (safeOutputsContent) {
           const safeOutputsMarkdown = formatSafeOutputsPreview(safeOutputsContent, { isPlainText: false });
           if (safeOutputsMarkdown) {
@@ -179,8 +185,14 @@ async function runLogParser(options) {
           }
         }
 
-        // Write original markdown to step summary if available
-        let fullMarkdown = markdown;
+        // Wrap the original markdown in a details/summary section (open by default)
+        const wrappedAgentLog = wrapAgentLogInSection(markdown, {
+          parserName,
+          open: true,
+        });
+
+        // Write wrapped markdown to step summary if available
+        let fullMarkdown = wrappedAgentLog;
         if (safeOutputsContent) {
           const safeOutputsMarkdown = formatSafeOutputsPreview(safeOutputsContent, { isPlainText: false });
           if (safeOutputsMarkdown) {
diff --git a/actions/setup/js/log_parser_bootstrap.test.cjs b/actions/setup/js/log_parser_bootstrap.test.cjs
index 9007de6e788..57c08a8ba29 100644
--- a/actions/setup/js/log_parser_bootstrap.test.cjs
+++ b/actions/setup/js/log_parser_bootstrap.test.cjs
@@ -45,7 +45,7 @@ describe("log_parser_bootstrap.cjs", () => {
           (runLogParser({ parseLog: mockParseLog, parserName: "TestParser" }),
             expect(mockParseLog).toHaveBeenCalledWith("Test log content"),
             expect(mockCore.info).toHaveBeenCalledWith("TestParser log parsed successfully"),
-            expect(mockCore.summary.addRaw).toHaveBeenCalledWith("## Parsed Log\n\nSuccess!"),
+            expect(mockCore.summary.addRaw).toHaveBeenCalledWith("<details open>\n<summary>🤖 TestParser CLI Session</summary>\n\n## Parsed Log\n\nSuccess!\n</details>"),
             expect(mockCore.summary.write).toHaveBeenCalled(),
             fs.unlinkSync(logFile),
             fs.rmdirSync(tmpDir));
@@ -57,7 +57,7 @@ describe("log_parser_bootstrap.cjs", () => {
           const mockParseLog = vi.fn().mockReturnValue({ markdown: "## Result\n", mcpFailures: [], maxTurnsHit: !1 });
           (runLogParser({ parseLog: mockParseLog, parserName: "TestParser" }),
             expect(mockCore.info).toHaveBeenCalledWith("TestParser log parsed successfully"),
-            expect(mockCore.summary.addRaw).toHaveBeenCalledWith("## Result\n"),
+            expect(mockCore.summary.addRaw).toHaveBeenCalledWith("<details open>\n<summary>🤖 TestParser CLI Session</summary>\n\n## Result\n\n</details>"),
             expect(mockCore.setFailed).not.toHaveBeenCalled(),
             fs.unlinkSync(logFile),
             fs.rmdirSync(tmpDir));
diff --git a/actions/setup/js/log_parser_shared.cjs b/actions/setup/js/log_parser_shared.cjs
index 7fa71f9c96f..f6c918bff69 100644
--- a/actions/setup/js/log_parser_shared.cjs
+++ b/actions/setup/js/log_parser_shared.cjs
@@ -1414,6 +1414,28 @@ function generateCopilotCliStyleSummary(logEntries, options = {}) {
   return lines.join("\n");
 }
 
+/**
+ * Wraps agent log markdown in a details/summary section
+ * @param {string} markdown - The agent log markdown content
+ * @param {Object} options - Configuration options
+ * @param {string} [options.parserName="Agent"] - Name of the parser (e.g., "Copilot", "Claude")
+ * @param {boolean} [options.open=true] - Whether the section should be open by default
+ * @returns {string} Wrapped markdown in details/summary tags
+ */
+function wrapAgentLogInSection(markdown, options = {}) {
+  const { parserName = "Agent", open = true } = options;
+
+  if (!markdown || markdown.trim().length === 0) {
+    return "";
+  }
+
+  const openAttr = open ? " open" : "";
+  const emoji = "🤖";
+  const title = `${emoji} ${parserName} CLI Session`;
+
+  return `<details${openAttr}>\n<summary>${title}</summary>\n\n${markdown}\n</details>`;
+}
+
 /**
  * Formats safe outputs preview for display in logs
  * @param {string} safeOutputsContent - The raw JSONL content from safe outputs file
@@ -1591,6 +1613,7 @@ module.exports = {
   formatToolCallAsDetails,
   generatePlainTextSummary,
   generateCopilotCliStyleSummary,
+  wrapAgentLogInSection,
   formatSafeOutputsPreview,
   wrapLogParser,
   createEngineLogParser,
diff --git a/actions/setup/js/log_parser_shared.test.cjs b/actions/setup/js/log_parser_shared.test.cjs
index f1a8b8e5d9a..6b157c27b47 100644
--- a/actions/setup/js/log_parser_shared.test.cjs
+++ b/actions/setup/js/log_parser_shared.test.cjs
@@ -2087,6 +2087,66 @@ describe("log_parser_shared.cjs", () => {
     });
   });
 
+  describe("wrapAgentLogInSection", () => {
+    it("should wrap markdown in details/summary with default open attribute", async () => {
+      const { wrapAgentLogInSection } = await import("./log_parser_shared.cjs");
+
+      const markdown = "```\nConversation:\n\nAgent: Hello\n```";
+      const result = wrapAgentLogInSection(markdown, { parserName: "Copilot" });
+
+      expect(result).toContain("<details open>");
+      expect(result).toContain("<summary>🤖 Copilot CLI Session</summary>");
+      expect(result).toContain(markdown);
+      expect(result).toContain("</details>");
+    });
+
+    it("should support custom parser names", async () => {
+      const { wrapAgentLogInSection } = await import("./log_parser_shared.cjs");
+
+      const markdown = "Test content";
+      const result = wrapAgentLogInSection(markdown, { parserName: "Claude" });
+
+      expect(result).toContain("🤖 Claude CLI Session");
+    });
+
+    it("should allow closed state when open is false", async () => {
+      const { wrapAgentLogInSection } = await import("./log_parser_shared.cjs");
+
+      const markdown = "Test content";
+      const result = wrapAgentLogInSection(markdown, { parserName: "Copilot", open: false });
+
+      expect(result).toContain("<details>");
+      expect(result).not.toContain("<details open>");
+    });
+
+    it("should default to Agent parser name when not provided", async () => {
+      const { wrapAgentLogInSection } = await import("./log_parser_shared.cjs");
+
+      const markdown = "Test content";
+      const result = wrapAgentLogInSection(markdown);
+
+      expect(result).toContain("🤖 Agent CLI Session");
+    });
+
+    it("should return empty string for empty or undefined markdown", async () => {
+      const { wrapAgentLogInSection } = await import("./log_parser_shared.cjs");
+
+      expect(wrapAgentLogInSection("")).toBe("");
+      expect(wrapAgentLogInSection("   ")).toBe("");
+    });
+
+    it("should properly escape markdown content", async () => {
+      const { wrapAgentLogInSection } = await import("./log_parser_shared.cjs");
+
+      const markdown = "Content with <tags> and `code`";
+      const result = wrapAgentLogInSection(markdown, { parserName: "Copilot" });
+
+      expect(result).toContain(markdown);
+      expect(result).toContain("<details open>");
+      expect(result).toContain("</details>");
+    });
+  });
+
   describe("wrapLogParser", () => {
     it("should call parser function and return result on success", async () => {
       const { wrapLogParser } = await import("./log_parser_shared.cjs");