This error usually happens when there’s a mistake in the API-request tool settings—most commonly a missing required field, an invalid JSON body, or a wrong URL/header format. To fix it, open your tool settings and carefully check that the method (GET/POST), URL, headers, and JSON body are all valid and correctly formatted. Make sure your JSON has no missing commas or brackets, and that the endpoint you’re calling actually works when tested separately in Postman or a browser. After correcting these fields, save the changes again—once the tool has valid data, it will publish without showing the “tool update failed” error.