fix: sanitize Gemini tool schema required fields (#64284) (thanks @xxxxxmax)

src/agents/schema/clean-for-gemini.test.ts

@@ -68,12 +68,21 @@ describe("cleanSchemaForGemini", () => {
     expect(cleaned.required).toBeUndefined();
   });
 
-  it("leaves required as-is when properties is absent", () => {
+  it("removes required from object schemas when properties is absent", () => {
     const cleaned = cleanSchemaForGemini({
       type: "object",
       required: ["a", "b"],
     }) as { required?: string[] };
 
+    expect(cleaned.required).toBeUndefined();
+  });
+
+  it("leaves required as-is for non-object schemas when properties is absent", () => {
+    const cleaned = cleanSchemaForGemini({
+      type: "array",
+      required: ["a", "b"],
+    }) as { required?: string[] };
+
     expect(cleaned.required).toEqual(["a", "b"]);
   });
 

src/agents/schema/clean-for-gemini.ts

@@ -214,12 +214,18 @@ function simplifyUnionVariants(params: { obj: Record<string, unknown>; variants:
 
 // Gemini rejects object schemas whose `required` entries do not exist in `properties`.
 function sanitizeRequiredFields(schema: Record<string, unknown>): Record<string, unknown> {
+  if (!Array.isArray(schema.required)) {
+    return schema;
+  }
+
   if (
-    !Array.isArray(schema.required) ||
     !schema.properties ||
     typeof schema.properties !== "object" ||
     Array.isArray(schema.properties)
   ) {
+    if (schema.type === "object") {
+      delete schema.required;
+    }
     return schema;
   }