diff --git a/actions/setup/js/checkout_pr_branch.cjs b/actions/setup/js/checkout_pr_branch.cjs
index dadf69ad85..a3310b3568 100644
--- a/actions/setup/js/checkout_pr_branch.cjs
+++ b/actions/setup/js/checkout_pr_branch.cjs
@@ -7,6 +7,8 @@
  */
 
 const { getErrorMessage } = require("./error_helpers.cjs");
+const { renderTemplate } = require("./messages_core.cjs");
+const fs = require("fs");
 
 async function main() {
   const eventName = context.eventName;
@@ -40,7 +42,17 @@ async function main() {
       core.info(`✅ Successfully checked out PR #${prNumber}`);
     }
   } catch (error) {
-    core.setFailed(`Failed to checkout PR branch: ${getErrorMessage(error)}`);
+    const errorMsg = getErrorMessage(error);
+
+    // Load and render step summary template
+    const templatePath = "/opt/gh-aw/prompts/pr_checkout_failure.md";
+    const template = fs.readFileSync(templatePath, "utf8");
+    const summaryContent = renderTemplate(template, {
+      error_message: errorMsg,
+    });
+
+    await core.summary.addRaw(summaryContent).write();
+    core.setFailed(`Failed to checkout PR branch: ${errorMsg}`);
   }
 }
 
diff --git a/actions/setup/js/checkout_pr_branch.test.cjs b/actions/setup/js/checkout_pr_branch.test.cjs
index af9958e4fc..c4deb67c05 100644
--- a/actions/setup/js/checkout_pr_branch.test.cjs
+++ b/actions/setup/js/checkout_pr_branch.test.cjs
@@ -10,6 +10,10 @@ describe("checkout_pr_branch.cjs", () => {
     mockCore = {
       info: vi.fn(),
       setFailed: vi.fn(),
+      summary: {
+        addRaw: vi.fn().mockReturnThis(),
+        write: vi.fn().mockResolvedValue(undefined),
+      },
     };
 
     // Mock exec
@@ -58,6 +62,47 @@ describe("checkout_pr_branch.cjs", () => {
       if (module === "./error_helpers.cjs") {
         return { getErrorMessage: error => (error instanceof Error ? error.message : String(error)) };
       }
+      if (module === "./messages_core.cjs") {
+        return {
+          renderTemplate: (template, context) => {
+            return template.replace(/\{(\w+)\}/g, (match, key) => {
+              const value = context[key];
+              return value !== undefined && value !== null ? String(value) : match;
+            });
+          },
+        };
+      }
+      if (module === "fs") {
+        return {
+          readFileSync: (path, encoding) => {
+            // Return mock template for pr_checkout_failure.md
+            if (path.includes("pr_checkout_failure.md")) {
+              return `## ❌ Failed to Checkout PR Branch
+
+**Error:** {error_message}
+
+### Possible Reasons
+
+This failure typically occurs when:
+- The pull request has been closed or merged
+- The branch has been deleted
+- There are insufficient permissions to access the PR
+
+### What to Do
+
+If the pull request is closed, you may need to:
+1. Reopen the pull request, or
+2. Create a new pull request with the changes
+
+If the pull request is still open, verify that:
+- The branch still exists in the repository
+- You have the necessary permissions to access it
+`;
+            }
+            throw new Error(`Unexpected file read: ${path}`);
+          },
+        };
+      }
       throw new Error(`Module ${module} not mocked in test`);
     };
 
@@ -92,6 +137,14 @@ describe("checkout_pr_branch.cjs", () => {
 
       await runScript();
 
+      expect(mockCore.summary.addRaw).toHaveBeenCalled();
+      expect(mockCore.summary.write).toHaveBeenCalled();
+
+      const summaryCall = mockCore.summary.addRaw.mock.calls[0][0];
+      expect(summaryCall).toContain("Failed to Checkout PR Branch");
+      expect(summaryCall).toContain("git fetch failed");
+      expect(summaryCall).toContain("pull request has been closed");
+
       expect(mockCore.setFailed).toHaveBeenCalledWith("Failed to checkout PR branch: git fetch failed");
     });
 
@@ -101,6 +154,13 @@ describe("checkout_pr_branch.cjs", () => {
 
       await runScript();
 
+      expect(mockCore.summary.addRaw).toHaveBeenCalled();
+      expect(mockCore.summary.write).toHaveBeenCalled();
+
+      const summaryCall = mockCore.summary.addRaw.mock.calls[0][0];
+      expect(summaryCall).toContain("Failed to Checkout PR Branch");
+      expect(summaryCall).toContain("git checkout failed");
+
       expect(mockCore.setFailed).toHaveBeenCalledWith("Failed to checkout PR branch: git checkout failed");
     });
   });
@@ -129,6 +189,14 @@ describe("checkout_pr_branch.cjs", () => {
 
       await runScript();
 
+      expect(mockCore.summary.addRaw).toHaveBeenCalled();
+      expect(mockCore.summary.write).toHaveBeenCalled();
+
+      const summaryCall = mockCore.summary.addRaw.mock.calls[0][0];
+      expect(summaryCall).toContain("Failed to Checkout PR Branch");
+      expect(summaryCall).toContain("gh pr checkout failed");
+      expect(summaryCall).toContain("pull request has been closed");
+
       expect(mockCore.setFailed).toHaveBeenCalledWith("Failed to checkout PR branch: gh pr checkout failed");
     });
 
diff --git a/actions/setup/md/pr_checkout_failure.md b/actions/setup/md/pr_checkout_failure.md
new file mode 100644
index 0000000000..a0eb122f69
--- /dev/null
+++ b/actions/setup/md/pr_checkout_failure.md
@@ -0,0 +1,20 @@
+## ❌ Failed to Checkout PR Branch
+
+**Error:** {error_message}
+
+### Possible Reasons
+
+This failure typically occurs when:
+- The pull request has been closed or merged
+- The branch has been deleted
+- There are insufficient permissions to access the PR
+
+### What to Do
+
+If the pull request is closed, you may need to:
+1. Reopen the pull request, or
+2. Create a new pull request with the changes
+
+If the pull request is still open, verify that:
+- The branch still exists in the repository
+- You have the necessary permissions to access it