diff --git a/plane_mcp/tools/work_items.py b/plane_mcp/tools/work_items.py
index 49ceac1..a4763c2 100644
--- a/plane_mcp/tools/work_items.py
+++ b/plane_mcp/tools/work_items.py
@@ -178,6 +178,13 @@ def retrieve_work_item(
         """
         client, workspace_slug = get_plane_client_context()
 
+        # Always expand assignees to get UserLite objects instead of bare UUIDs.
+        if expand:
+            if "assignees" not in expand:
+                expand = f"{expand},assignees"
+        else:
+            expand = "assignees"
+
         params = RetrieveQueryParams(
             expand=expand,
             fields=fields,
@@ -221,6 +228,13 @@ def retrieve_work_item_by_identifier(
         """
         client, workspace_slug = get_plane_client_context()
 
+        # Always expand assignees to get UserLite objects instead of bare UUIDs.
+        if expand:
+            if "assignees" not in expand:
+                expand = f"{expand},assignees"
+        else:
+            expand = "assignees"
+
         params = RetrieveQueryParams(
             expand=expand,
             fields=fields,