diff --git a/.changeset/fix-google-primitive-tool-results.md b/.changeset/fix-google-primitive-tool-results.md
new file mode 100644
index 00000000000..97194ea175c
--- /dev/null
+++ b/.changeset/fix-google-primitive-tool-results.md
@@ -0,0 +1,5 @@
+---
+"@effect/ai-google": patch
+---
+
+Wrap primitive tool results in an object before sending to Gemini
diff --git a/packages/ai/google/src/GoogleLanguageModel.ts b/packages/ai/google/src/GoogleLanguageModel.ts
index 760022de4bd..adf1effc39b 100644
--- a/packages/ai/google/src/GoogleLanguageModel.ts
+++ b/packages/ai/google/src/GoogleLanguageModel.ts
@@ -386,11 +386,12 @@ const prepareMessages: (
           const parts: Array<typeof Generated.Part.Encoded> = []
 
           for (const part of message.content) {
+            const response = Predicate.isRecord(part.result) ? part.result : { result: part.result }
             parts.push({
               functionResponse: {
                 id: part.id,
                 name: part.name,
-                response: part.result as any
+                response: response as any
               }
             })
           }