diff --git a/minimax_mcp/server.py b/minimax_mcp/server.py
index ce74c5e..d625623 100644
--- a/minimax_mcp/server.py
+++ b/minimax_mcp/server.py
@@ -87,9 +87,6 @@ def text_to_audio(
     format: str = DEFAULT_FORMAT,
     language_boost: str = DEFAULT_LANGUAGE_BOOST,
 ):
-    if not text:
-        raise MinimaxRequestError("Text is required.")
-
     payload = {
         "model": model,
         "text": text,
@@ -111,6 +108,9 @@ def text_to_audio(
     if resource_mode == RESOURCE_MODE_URL:
         payload["output_format"] = "url"
     try:
+        if not text:
+            raise MinimaxRequestError("Text is required.")
+
         response_data = api_client.post("/v1/t2a_v2", json=payload)
         audio_data = response_data.get('data', {}).get('audio', '')
         
diff --git a/tests/test_server.py b/tests/test_server.py
new file mode 100644
index 0000000..06b9655
--- /dev/null
+++ b/tests/test_server.py
@@ -0,0 +1,21 @@
+import importlib
+import sys
+
+from mcp.types import TextContent
+
+
+def load_server(monkeypatch):
+    monkeypatch.setenv("MINIMAX_API_KEY", "test-key")
+    monkeypatch.setenv("MINIMAX_API_HOST", "https://api.example.com")
+    sys.modules.pop("minimax_mcp.server", None)
+    return importlib.import_module("minimax_mcp.server")
+
+
+def test_text_to_audio_returns_text_content_for_empty_text(monkeypatch):
+    server = load_server(monkeypatch)
+
+    result = server.text_to_audio(text="")
+
+    assert isinstance(result, TextContent)
+    assert result.type == "text"
+    assert result.text == "Failed to generate audio: Text is required."