Add available tones property to siren entity description (#70216)

* Fix siren entity description and available tones property

* Add test

* Fix bug

* Add coverage

tests/components/siren/test_init.py

@@ -3,7 +3,11 @@ from unittest.mock import MagicMock
 
 import pytest
 
-from homeassistant.components.siren import SirenEntity, process_turn_on_params
+from homeassistant.components.siren import (
+    SirenEntity,
+    SirenEntityDescription,
+    process_turn_on_params,
+)
 from homeassistant.components.siren.const import SirenEntityFeature
 
 
@@ -12,10 +16,20 @@ class MockSirenEntity(SirenEntity):
 
     _attr_is_on = True
 
-    def __init__(self, supported_features=0, available_tones=None):
+    def __init__(
+        self,
+        supported_features=0,
+        available_tones_as_attr=None,
+        available_tones_in_desc=None,
+    ):
         """Initialize mock siren entity."""
         self._attr_supported_features = supported_features
-        self._attr_available_tones = available_tones
+        if available_tones_as_attr is not None:
+            self._attr_available_tones = available_tones_as_attr
+        elif available_tones_in_desc is not None:
+            self.entity_description = SirenEntityDescription(
+                "mock", available_tones=available_tones_in_desc
+            )
 
 
 async def test_sync_turn_on(hass):
@@ -50,11 +64,23 @@ async def test_no_available_tones(hass):
 
 async def test_available_tones_list(hass):
     """Test that valid tones from tone list will get passed in."""
-    siren = MockSirenEntity(SirenEntityFeature.TONES, ["a", "b"])
+    siren = MockSirenEntity(
+        SirenEntityFeature.TONES, available_tones_as_attr=["a", "b"]
+    )
     siren.hass = hass
     assert process_turn_on_params(siren, {"tone": "a"}) == {"tone": "a"}
 
 
+async def test_available_tones(hass):
+    """Test different available tones scenarios."""
+    siren = MockSirenEntity(
+        SirenEntityFeature.TONES, available_tones_in_desc=["a", "b"]
+    )
+    assert siren.available_tones == ["a", "b"]
+    siren = MockSirenEntity(SirenEntityFeature.TONES)
+    assert siren.available_tones is None
+
+
 async def test_available_tones_dict(hass):
     """Test that valid tones from available_tones dict will get passed in."""
     siren = MockSirenEntity(SirenEntityFeature.TONES, {1: "a", 2: "b"})