diff --git a/.stats.yml b/.stats.yml
index 68c3aa80..ff322255 100644
--- a/.stats.yml
+++ b/.stats.yml
@@ -1,2 +1,2 @@
 configured_endpoints: 2
-openapi_spec_url: https://storage.googleapis.com/stainless-sdk-openapi-specs/anthropic-70873642f89316fbc45ceaccd3583971d0eb59d433f7864ca2fa8c321a320b4c.yml
+openapi_spec_url: https://storage.googleapis.com/stainless-sdk-openapi-specs/anthropic-ce067ae8303fa9b7aae2e8ebf0b6e9e41509f169ba93c1807e6ed9c9e541be1a.yml
diff --git a/src/resources/messages.ts b/src/resources/messages.ts
index 6ce8623d..e55c3c6a 100644
--- a/src/resources/messages.ts
+++ b/src/resources/messages.ts
@@ -332,7 +332,7 @@ export interface ToolResultBlockParam {
 
   type: 'tool_result';
 
-  content?: Array<TextBlockParam | ImageBlockParam>;
+  content?: string | Array<TextBlockParam | ImageBlockParam>;
 
   is_error?: boolean;
 }