diff --git a/src/lib/debug.test.ts b/src/lib/debug.test.ts
index 7aa76d195..f3a4a8387 100644
--- a/src/lib/debug.test.ts
+++ b/src/lib/debug.test.ts
@@ -3,7 +3,7 @@
 
 import { describe, it, expect } from "vitest";
 // Import from compiled dist/ so coverage is attributed correctly.
-import { redact } from "../../dist/lib/debug";
+import { getDebugCompletionMessages, redact } from "../../dist/lib/debug";
 
 describe("redact", () => {
   it("redacts NVIDIA_API_KEY=value patterns", () => {
@@ -50,3 +50,16 @@ describe("redact", () => {
     expect(redact(clean)).toBe(clean);
   });
 });
+
+describe("getDebugCompletionMessages", () => {
+  it("suggests --output when no tarball path is provided", () => {
+    expect(getDebugCompletionMessages()).toEqual([
+      "Done. If filing a bug, run with --output and attach the tarball to your issue:",
+      "  nemoclaw debug --output /tmp/nemoclaw-debug.tar.gz",
+    ]);
+  });
+
+  it("omits the redundant --output hint when a tarball was already written", () => {
+    expect(getDebugCompletionMessages("/tmp/nemoclaw-debug.tar.gz")).toEqual([]);
+  });
+});
diff --git a/src/lib/debug.ts b/src/lib/debug.ts
index aa898cf44..9dcf68bf4 100644
--- a/src/lib/debug.ts
+++ b/src/lib/debug.ts
@@ -446,6 +446,10 @@ function collectKernelMessages(collectDir: string): void {
 // Tarball
 // ---------------------------------------------------------------------------
 
+/**
+ * Archive the collected diagnostics into a tarball and print the sharing
+ * guidance that goes with the generated file.
+ */
 function createTarball(collectDir: string, output: string): void {
   spawnSync("tar", ["czf", output, "-C", dirname(collectDir), basename(collectDir)], {
     stdio: "inherit",
@@ -458,10 +462,30 @@ function createTarball(collectDir: string, output: string): void {
   info("Attach this file to your GitHub issue.");
 }
 
+/**
+ * Return the final user-facing completion lines for the debug command.
+ * When a tarball was already written, the tarball creation step has already
+ * printed the attachment guidance, so we do not repeat it here.
+ */
+export function getDebugCompletionMessages(output?: string): string[] {
+  if (output) {
+    return [];
+  }
+
+  return [
+    "Done. If filing a bug, run with --output and attach the tarball to your issue:",
+    "  nemoclaw debug --output /tmp/nemoclaw-debug.tar.gz",
+  ];
+}
+
 // ---------------------------------------------------------------------------
 // Main entry point
 // ---------------------------------------------------------------------------
 
+/**
+ * Collect local and sandbox diagnostics for a NemoClaw environment and
+ * optionally bundle the results into a tarball for issue reporting.
+ */
 export function runDebug(opts: DebugOptions = {}): void {
   const quick = opts.quick ?? false;
   const output = opts.output ?? "";
@@ -504,8 +528,9 @@ export function runDebug(opts: DebugOptions = {}): void {
     }
 
     console.log("");
-    info("Done. If filing a bug, run with --output and attach the tarball to your issue:");
-    info("  nemoclaw debug --output /tmp/nemoclaw-debug.tar.gz");
+    for (const message of getDebugCompletionMessages(output)) {
+      info(message);
+    }
   } finally {
     rmSync(collectDir, { recursive: true, force: true });
   }