diff --git a/python/packages/core/agent_framework/_types.py b/python/packages/core/agent_framework/_types.py
index 17dba475e3e..4b8572e884a 100644
--- a/python/packages/core/agent_framework/_types.py
+++ b/python/packages/core/agent_framework/_types.py
@@ -1535,8 +1535,17 @@ def from_dict(cls: type[ContentT], data: Mapping[str, Any]) -> ContentT:
 
         # Special handling for DataContent with data and media_type
         if content_type == "data" and "data" in remaining and "media_type" in remaining:
-            # Use from_data() to properly create the DataContent with URI
-            return cls.from_data(remaining["data"], remaining["media_type"])
+            # Use from_data() to properly create the DataContent with URI. The three
+            # fields popped above are passed on explicitly: this branch returns before
+            # the constructor below, so leaving them out dropped on a data content what
+            # every other content type keeps.
+            return cls.from_data(
+                remaining["data"],
+                remaining["media_type"],
+                annotations=annotations,
+                additional_properties=additional_properties,
+                raw_representation=raw_representation,
+            )
 
         # Handle nested Content objects (e.g., function_call in function_approval_request)
         if (function_call := remaining.get("function_call")) and isinstance(function_call, dict):
diff --git a/python/packages/core/tests/core/test_types.py b/python/packages/core/tests/core/test_types.py
index a6797b30449..585a654a3df 100644
--- a/python/packages/core/tests/core/test_types.py
+++ b/python/packages/core/tests/core/test_types.py
@@ -2607,6 +2607,70 @@ def test_content_roundtrip_preserves_compaction_annotation_dict() -> None:
     assert annotation[GROUP_TOKEN_COUNT_KEY] is None
 
 
+def test_content_from_dict_data_keeps_annotations_and_metadata() -> None:
+    """The `data` + `media_type` branch must not lose what every other type keeps.
+
+    `from_dict` pops `annotations`, `additional_properties` and `raw_representation`
+    before dispatching, then returns early for a data content. `from_data` accepts
+    all three, but they were not being passed, so they were silently dropped -- and
+    this runs inside `Message.from_dict` and `ChatResponse.from_dict`.
+    """
+    content = Content.from_dict({
+        "type": "data",
+        "data": b"hello",
+        "media_type": "text/plain",
+        "annotations": [{"type": "citation", "title": "t"}],
+        "additional_properties": {"origin": "upload"},
+        "raw_representation": "provider-blob",
+    })
+
+    assert content.type == "data"
+    assert content.uri == "data:text/plain;base64,aGVsbG8="
+    assert content.annotations == [{"type": "citation", "title": "t"}]
+    assert content.additional_properties == {"origin": "upload"}
+    assert content.raw_representation == "provider-blob"
+
+
+def test_content_from_dict_data_matches_other_types_on_metadata() -> None:
+    """Same mapping shape, two content types, same treatment of the extra fields."""
+    common = {
+        "additional_properties": {"origin": "upload"},
+        "raw_representation": "provider-blob",
+    }
+    data_content = Content.from_dict({
+        "type": "data",
+        "data": b"hello",
+        "media_type": "text/plain",
+        **common,
+    })
+    uri_content = Content.from_dict({
+        "type": "uri",
+        "uri": "https://example.com/x.png",
+        "media_type": "image/png",
+        **common,
+    })
+
+    assert data_content.additional_properties == uri_content.additional_properties
+    assert data_content.raw_representation == uri_content.raw_representation
+
+
+def test_message_from_dict_keeps_data_content_metadata() -> None:
+    """Through the reachable path: rebuilding a message from its mapping."""
+    message = Message.from_dict({
+        "role": "user",
+        "contents": [
+            {
+                "type": "data",
+                "data": b"hello",
+                "media_type": "text/plain",
+                "additional_properties": {"origin": "upload"},
+            }
+        ],
+    })
+
+    assert message.contents[0].additional_properties == {"origin": "upload"}
+
+
 def test_content_from_dict_via_json() -> None:
     """Test Content.from_dict with data parsed from a JSON string."""
     data = json.loads(json.dumps({"type": "text", "text": "Hello world"}))