diff --git a/calibre/agent-harness/cli_anything/calibre/calibre_cli.py b/calibre/agent-harness/cli_anything/calibre/calibre_cli.py
index 67fda52ff..e5a938951 100644
--- a/calibre/agent-harness/cli_anything/calibre/calibre_cli.py
+++ b/calibre/agent-harness/cli_anything/calibre/calibre_cli.py
@@ -264,15 +264,20 @@ def books_list(ctx, search, sort, limit, fields):
         if not book_list:
             click.echo("  No books found.")
         else:
-            click.echo(f"  {'ID':<5} {'Title':<40} {'Authors':<30} {'Formats'}")
-            click.echo(f"  {'─'*5} {'─'*40} {'─'*30} {'─'*20}")
+            # Determine columns from actual returned fields (id is always first)
+            actual_fields = list(book_list[0].keys())
+            non_id_fields = [f for f in actual_fields if f != "id"]
+
+            # Build header dynamically
+            header = f"  {'ID':<5} " + " ".join(f"{f.capitalize():<30}" for f in non_id_fields)
+            sep = f"  {'─'*5} " + " ".join(f"{'─'*30}" for _ in non_id_fields)
+            click.echo(header)
+            click.echo(sep)
             for b in book_list:
-                click.echo(
-                    f"  {b.get('id', ''):<5} "
-                    f"{str(b.get('title', ''))[:40]:<40} "
-                    f"{str(b.get('authors', ''))[:30]:<30} "
-                    f"{b.get('formats', '')}"
+                row = f"  {b.get('id', ''):<5} " + " ".join(
+                    f"{str(b.get(f, ''))[:30]:<30}" for f in non_id_fields
                 )
+                click.echo(row)
 
 
 @books.command("search")
diff --git a/calibre/agent-harness/cli_anything/calibre/tests/test_full_e2e.py b/calibre/agent-harness/cli_anything/calibre/tests/test_full_e2e.py
index af57e64c3..9afde7f04 100644
--- a/calibre/agent-harness/cli_anything/calibre/tests/test_full_e2e.py
+++ b/calibre/agent-harness/cli_anything/calibre/tests/test_full_e2e.py
@@ -199,6 +199,21 @@ class TestLibraryOperations(CalibreTestMixin, unittest.TestCase):
         self.assertIn("title", book)
         print(f"\n  list_books[0]: {book}")
 
+    def test_list_books_custom_fields(self):
+        """list_books with explicit fields returns exactly those fields per book."""
+        from cli_anything.calibre.core.library import list_books
+        requested = ["id", "title", "tags"]
+        books = list_books(self.lib_dir, fields=requested)
+        self.assertGreater(len(books), 0)
+        book = books[0]
+        # Requested fields must be present
+        for field in requested:
+            self.assertIn(field, book, f"Missing field: {field}")
+        # Non-requested fields must be absent
+        for field in ("authors", "series", "rating"):
+            self.assertNotIn(field, book, f"Unexpected field: {field}")
+        print(f"\n  list_books(fields={requested})[0]: {book}")
+
     def test_search_books(self):
         from cli_anything.calibre.core.library import search_books
         ids = search_books(self.lib_dir, "title:Foundation")