diff --git a/.gitignore b/.gitignore
index 0772ad4d..76eee8c3 100644
--- a/.gitignore
+++ b/.gitignore
@@ -8,3 +8,4 @@ dist/
 compile_commands.json
 .envrc.local
 /src/glide.ts
+.vscode/
\ No newline at end of file
diff --git a/src/glide/browser/base/content/browser-commandline.mts b/src/glide/browser/base/content/browser-commandline.mts
index f58f33ad..c400395e 100644
--- a/src/glide/browser/base/content/browser-commandline.mts
+++ b/src/glide/browser/base/content/browser-commandline.mts
@@ -214,8 +214,21 @@ export class TabsCompletionSource implements GlideCompletionSource<TabCompletion
           ],
         }),
 
-        async accept() {
-          gBrowser.selectedTab = tab;
+        async accept(ctx) {
+          const input = ctx.input.trim();
+          const parts = input.split(" ");
+          const arg = parts[1];
+
+          // User typed "tab " with no arg - select the focused tab from completion list
+          if (arg === undefined || arg === "") {
+            gBrowser.selectedTab = tab;
+            GlideBrowser.remove_notification("glide-excmd-error");
+            return;
+          }
+
+          // User typed "tab <something>" - execute through GlideExcmds
+          // This handles both valid indices and invalid input (which will show an error)
+          await GlideExcmds.execute(input as any);
         },
         async delete() {
           gBrowser.removeTab(this.tab);
diff --git a/src/glide/browser/base/content/browser-excmds.mts b/src/glide/browser/base/content/browser-excmds.mts
index fbbddd3d..1ddedef4 100644
--- a/src/glide/browser/base/content/browser-excmds.mts
+++ b/src/glide/browser/base/content/browser-excmds.mts
@@ -106,11 +106,17 @@ class GlideExcmdsClass {
     command: glide.ExcmdValue,
     props?: SetOptional<ExecuteProps, "args">,
   ): Promise<void> {
+    const command_name = typeof command === "string" ? extract_command_name(command) : command.name;
+
     try {
       await this.#execute(command, {
         ...props,
         args: { ...this.#parse_args(command), tab_id: GlideBrowser.active_tab_id, ...props?.args },
       });
+
+      if (!command_name.includes("commandline_")) {
+        GlideBrowser.remove_notification("glide-excmd-error");
+      }
     } catch (err) {
       GlideBrowser._log.error(err);
 
diff --git a/src/glide/browser/base/content/test/commandline/browser_commandline.ts b/src/glide/browser/base/content/test/commandline/browser_commandline.ts
index 9d210f22..c3c05409 100644
--- a/src/glide/browser/base/content/test/commandline/browser_commandline.ts
+++ b/src/glide/browser/base/content/test/commandline/browser_commandline.ts
@@ -725,3 +725,237 @@ add_task(async function test_commandline_close() {
   is(result, true, "close() should return true when the commandline was open");
   await wait_for_mode("normal");
 });
+
+add_task(async function test_error_notification_tab_missing_args() {
+  await reload_config(function _() {});
+
+  await BrowserTestUtils.withNewTab(FILE, async () => {
+    await keys(":tab<CR>");
+    await waiter(() => gNotificationBox.getNotificationWithValue("glide-excmd-error")).ok();
+
+    const notification = gNotificationBox.getNotificationWithValue("glide-excmd-error")!;
+    ok(
+      notification.shadowRoot.querySelector(".message")?.textContent?.includes("tab_index"),
+      "error message should mention missing 'tab_index' argument",
+    );
+    gNotificationBox.removeNotification(notification);
+  });
+});
+
+add_task(async function test_error_notification_tab_invalid_index() {
+  await reload_config(function _() {});
+
+  await BrowserTestUtils.withNewTab(FILE, async () => {
+    await keys(":tab 999<CR>");
+    await waiter(() => gNotificationBox.getNotificationWithValue("glide-excmd-error")).ok();
+
+    const notification = gNotificationBox.getNotificationWithValue("glide-excmd-error")!;
+    ok(
+      notification.shadowRoot.querySelector(".message")?.textContent?.includes("could not find a tab"),
+      "error message should indicate tab not found",
+    );
+    gNotificationBox.removeNotification(notification);
+  });
+});
+
+add_task(async function test_error_notification_set_missing_args() {
+  await reload_config(function _() {});
+
+  await BrowserTestUtils.withNewTab(FILE, async () => {
+    await keys(":set<CR>");
+    await waiter(() => gNotificationBox.getNotificationWithValue("glide-excmd-error")).ok();
+
+    gNotificationBox.removeNotification(gNotificationBox.getNotificationWithValue("glide-excmd-error")!);
+  });
+});
+
+add_task(async function test_error_notification_set_invalid_option() {
+  await reload_config(function _() {});
+
+  await BrowserTestUtils.withNewTab(FILE, async () => {
+    await keys(":set invalid_option_name 123<CR>");
+    await waiter(() => gNotificationBox.getNotificationWithValue("glide-excmd-error")).ok();
+
+    const notification = gNotificationBox.getNotificationWithValue("glide-excmd-error")!;
+    ok(
+      notification.shadowRoot.querySelector(".message")?.textContent?.includes("not a valid option"),
+      "error message should indicate invalid option",
+    );
+    gNotificationBox.removeNotification(notification);
+  });
+});
+
+add_task(async function test_error_notification_mode_change_missing_args() {
+  await reload_config(function _() {});
+
+  await BrowserTestUtils.withNewTab(FILE, async () => {
+    await keys(":mode_change<CR>");
+    await waiter(() => gNotificationBox.getNotificationWithValue("glide-excmd-error")).ok();
+
+    gNotificationBox.removeNotification(gNotificationBox.getNotificationWithValue("glide-excmd-error")!);
+  });
+});
+
+add_task(async function test_error_notification_keys_missing_args() {
+  await reload_config(function _() {});
+
+  await BrowserTestUtils.withNewTab(FILE, async () => {
+    await keys(":keys<CR>");
+    await waiter(() => gNotificationBox.getNotificationWithValue("glide-excmd-error")).ok();
+
+    const notification = gNotificationBox.getNotificationWithValue("glide-excmd-error")!;
+    ok(
+      notification.shadowRoot.querySelector(".message")?.textContent?.includes("keyseq"),
+      "error message should mention missing 'keyseq' argument",
+    );
+    gNotificationBox.removeNotification(notification);
+  });
+});
+
+add_task(async function test_error_notification_unmap_missing_args() {
+  await reload_config(function _() {});
+
+  await BrowserTestUtils.withNewTab(FILE, async () => {
+    await keys(":unmap<CR>");
+    await waiter(() => gNotificationBox.getNotificationWithValue("glide-excmd-error")).ok();
+
+    const notification = gNotificationBox.getNotificationWithValue("glide-excmd-error")!;
+    ok(
+      notification.shadowRoot.querySelector(".message")?.textContent?.includes("lhs"),
+      "error message should mention missing 'lhs' argument",
+    );
+    gNotificationBox.removeNotification(notification);
+  });
+});
+
+add_task(async function test_error_notification_caret_move_missing_args() {
+  await reload_config(function _() {});
+
+  await BrowserTestUtils.withNewTab(FILE, async () => {
+    await keys(":caret_move<CR>");
+    await waiter(() => gNotificationBox.getNotificationWithValue("glide-excmd-error")).ok();
+
+    const notification = gNotificationBox.getNotificationWithValue("glide-excmd-error")!;
+    ok(
+      notification.shadowRoot.querySelector(".message")?.textContent?.includes("direction"),
+      "error message should mention missing 'direction' argument",
+    );
+    gNotificationBox.removeNotification(notification);
+  });
+});
+
+add_task(async function test_error_notification_cleared_tab_succeeds() {
+  await reload_config(function _() {});
+
+  await BrowserTestUtils.withNewTab(FILE, async () => {
+    await keys(":tab<CR>");
+    await waiter(() => gNotificationBox.getNotificationWithValue("glide-excmd-error")).ok();
+
+    await keys(":tab 0<CR>");
+    await waiter(() => gNotificationBox.getNotificationWithValue("glide-excmd-error") === null).ok();
+
+    is(
+      gNotificationBox.getNotificationWithValue("glide-excmd-error"),
+      null,
+      "error notification should be cleared after successful tab command",
+    );
+  });
+});
+
+add_task(async function test_error_notification_cleared_mode_change_succeeds() {
+  await reload_config(function _() {});
+
+  await BrowserTestUtils.withNewTab(FILE, async () => {
+    await keys(":mode_change<CR>");
+    await waiter(() => gNotificationBox.getNotificationWithValue("glide-excmd-error")).ok();
+
+    await keys(":mode_change normal<CR>");
+    await waiter(() => gNotificationBox.getNotificationWithValue("glide-excmd-error") === null).ok();
+
+    is(
+      gNotificationBox.getNotificationWithValue("glide-excmd-error"),
+      null,
+      "error notification should be cleared after successful mode_change command",
+    );
+  });
+});
+
+add_task(async function test_error_notification_cleared_by_different_command() {
+  await reload_config(function _() {});
+
+  await BrowserTestUtils.withNewTab(FILE, async () => {
+    await keys(":tab<CR>");
+    await waiter(() => gNotificationBox.getNotificationWithValue("glide-excmd-error")).ok();
+
+    await keys(":reload<CR>");
+    await waiter(() => gNotificationBox.getNotificationWithValue("glide-excmd-error") === null).ok();
+
+    is(
+      gNotificationBox.getNotificationWithValue("glide-excmd-error"),
+      null,
+      "error notification should be cleared after a different successful command",
+    );
+  });
+});
+
+add_task(async function test_error_notification_cleared_by_different_command_with_args() {
+  await reload_config(function _() {});
+
+  await BrowserTestUtils.withNewTab(FILE, async () => {
+    await keys(":set<CR>");
+    await waiter(() => gNotificationBox.getNotificationWithValue("glide-excmd-error")).ok();
+
+    await keys(":mode_change normal<CR>");
+    await waiter(() => gNotificationBox.getNotificationWithValue("glide-excmd-error") === null).ok();
+
+    is(
+      gNotificationBox.getNotificationWithValue("glide-excmd-error"),
+      null,
+      "error notification should be cleared after a different successful command with args",
+    );
+  });
+});
+
+add_task(async function test_error_notification_cleared_via_tab_completion() {
+  await reload_config(function _() {});
+
+  await BrowserTestUtils.withNewTab(FILE, async () => {
+    await keys(":tab<CR>");
+    await waiter(() => gNotificationBox.getNotificationWithValue("glide-excmd-error")).ok();
+
+    await GlideTestUtils.commandline.open();
+    await keys("tab ");
+    await waiter(() => GlideTestUtils.commandline.current_source_header()).is("tabs");
+    await waiter(() => GlideTestUtils.commandline.visible_rows().length > 0).ok();
+    await keys("<CR>");
+
+    await waiter(() => gNotificationBox.getNotificationWithValue("glide-excmd-error") === null).ok();
+
+    is(
+      gNotificationBox.getNotificationWithValue("glide-excmd-error"),
+      null,
+      "error notification should be cleared after selecting tab via completion",
+    );
+  });
+});
+
+add_task(async function test_multiple_errors_cleared_by_one_success() {
+  await reload_config(function _() {});
+
+  await BrowserTestUtils.withNewTab(FILE, async () => {
+    await keys(":tab<CR>");
+    await waiter(() => gNotificationBox.getNotificationWithValue("glide-excmd-error")).ok();
+
+    await keys(":set<CR>");
+    await waiter(() => gNotificationBox.getNotificationWithValue("glide-excmd-error")).ok();
+
+    await keys(":tab 0<CR>");
+    await waiter(() => gNotificationBox.getNotificationWithValue("glide-excmd-error") === null).ok();
+
+    is(
+      gNotificationBox.getNotificationWithValue("glide-excmd-error"),
+      null,
+      "error notification should be cleared after any successful command",
+    );
+  });
+});