diff --git a/packages/core/data-transfer/src/engine/index.ts b/packages/core/data-transfer/src/engine/index.ts
index 2787953bc7..2f04bce86e 100644
--- a/packages/core/data-transfer/src/engine/index.ts
+++ b/packages/core/data-transfer/src/engine/index.ts
@@ -346,7 +346,7 @@ class TransferEngine<
     keys.forEach((key) => {
       const sourceSchema = sourceSchemas[key];
       const destinationSchema = destinationSchemas[key];
-      const schemaDiffs = compareSchemas(destinationSchema, sourceSchema, strategy);
+      const schemaDiffs = compareSchemas(sourceSchema, destinationSchema, strategy);
 
       if (schemaDiffs.length) {
         diffs[key] = schemaDiffs;
@@ -364,15 +364,19 @@ class TransferEngine<
               const path = diff.path.join('.');
 
               if (diff.kind === 'added') {
-                return `Added "${path}": "${diff.value}" (${diff.type})`;
+                return `${path} exists in destination schema but not in source schema`;
               }
 
               if (diff.kind === 'deleted') {
-                return `Removed "${path}"`;
+                return `${path} exists in source schema but not in destination schema`;
               }
 
               if (diff.kind === 'modified') {
-                return `Modified "${path}": "${diff.values[0]}" (${diff.types[0]}) => "${diff.values[1]}" (${diff.types[1]})`;
+                if (diff.types[0] === diff.types[1]) {
+                  return `Schema value changed at "${path}": "${diff.values[0]}" (${diff.types[0]}) => "${diff.values[1]}" (${diff.types[1]})`;
+                }
+
+                return `Schema has differing data types at "${path}": "${diff.values[0]}" (${diff.types[0]}) => "${diff.values[1]}" (${diff.types[1]})`;
               }
 
               throw new TransferEngineValidationError(`Invalid diff found for "${uid}"`, {
diff --git a/packages/core/data-transfer/src/utils/json.ts b/packages/core/data-transfer/src/utils/json.ts
index d305ee1cab..42001f48a2 100644
--- a/packages/core/data-transfer/src/utils/json.ts
+++ b/packages/core/data-transfer/src/utils/json.ts
@@ -38,14 +38,6 @@ export const diff = (a: unknown, b: unknown, ctx: Context = createContext()): Di
     return diffs;
   };
 
-  if (aType === 'undefined') {
-    return added();
-  }
-
-  if (bType === 'undefined') {
-    return deleted();
-  }
-
   if (isArray(a) && isArray(b)) {
     let k = 0;
 
@@ -77,6 +69,14 @@ export const diff = (a: unknown, b: unknown, ctx: Context = createContext()): Di
   }
 
   if (!isEqual(a, b)) {
+    if (aType === 'undefined') {
+      return added();
+    }
+
+    if (bType === 'undefined') {
+      return deleted();
+    }
+
     return modified();
   }