diff --git a/griptape/artifacts/image_artifact.py b/griptape/artifacts/image_artifact.py
index 616dc335a2..36170ee0d8 100644
--- a/griptape/artifacts/image_artifact.py
+++ b/griptape/artifacts/image_artifact.py
@@ -10,7 +10,7 @@ class ImageArtifact(BlobArtifact):
     """Stores image data.
 
     Attributes:
-        format: The format of the image data.
+        format: The format of the image data. Used when building the MIME type.
         width: The width of the image.
         height: The height of the image
     """
diff --git a/griptape/common/prompt_stack/contents/text_message_content.py b/griptape/common/prompt_stack/contents/text_message_content.py
index 39e678f28d..c862564f3f 100644
--- a/griptape/common/prompt_stack/contents/text_message_content.py
+++ b/griptape/common/prompt_stack/contents/text_message_content.py
@@ -4,7 +4,7 @@
 
 from attrs import define, field
 
-from griptape.artifacts import BaseArtifact, TextArtifact
+from griptape.artifacts import TextArtifact
 from griptape.common import BaseDeltaMessageContent, BaseMessageContent, TextDeltaMessageContent
 
 if TYPE_CHECKING:
@@ -13,7 +13,7 @@
 
 @define
 class TextMessageContent(BaseMessageContent):
-    artifact: BaseArtifact = field(metadata={"serializable": True})
+    artifact: TextArtifact = field(metadata={"serializable": True})
 
     @classmethod
     def from_deltas(cls, deltas: Sequence[BaseDeltaMessageContent]) -> TextMessageContent: