@cf/meta/llama-4-scout-17b-16e-instruct not returning valid JSON schema back

{

evaluation: 'This ad is completely incorrect. The title mentions Playstation 3, but the
  requested item is a GameBoy. The price is also listed as €0.00, which seems to be an error. The
  picture is likely not of a GameBoy either.',
    goodDeal: false
  }

const aiResp = await env.AI.run(
        "@cf/meta/llama-4-scout-17b-16e-instruct",
        {
          messages,
          response_format: {
            type: "json_schema",
            json_schema: {
              name: "DealEvaluation",
              schema: {
                type: "object",
                properties: {
                  evaluation: {
                    type: "string",
                    description:
                      "Brief explanation why this is or isn’t a good deal",
                  },
                  goodDeal: {
                    type: "boolean",
                    description: "Whether this is a good deal",
                  },
                },
                required: ["evaluation", "goodDeal"],
              },
            },
          },
        }
      );