fix overlong function names in provider requests (#10659)

crates/goose-provider-types/src/formats/openai.rs

@@ -1577,10 +1577,15 @@ pub(crate) fn openai_reasoning_efforts_for_model(model_name: &str) -> &'static [
     }
 }
 
+const MAX_FUNCTION_NAME_LENGTH: usize = 128;
+
 pub fn sanitize_function_name(name: &str) -> String {
     static RE: OnceLock<Regex> = OnceLock::new();
     let re = RE.get_or_init(|| Regex::new(r"[^a-zA-Z0-9_-]").unwrap());
-    re.replace_all(name, "_").to_string()
+    re.replace_all(name, "_")
+        .chars()
+        .take(MAX_FUNCTION_NAME_LENGTH)
+        .collect()
 }
 
 pub fn is_valid_function_name(name: &str) -> bool {
@@ -4160,12 +4165,23 @@ data: [DONE]"#;
         assert_eq!(sanitize_function_name("hello-world"), "hello-world");
         assert_eq!(sanitize_function_name("hello world"), "hello_world");
         assert_eq!(sanitize_function_name("hello@world"), "hello_world");
+        assert_eq!(
+            sanitize_function_name(&"a".repeat(MAX_FUNCTION_NAME_LENGTH)),
+            "a".repeat(MAX_FUNCTION_NAME_LENGTH)
+        );
+        assert_eq!(
+            sanitize_function_name(&"a".repeat(MAX_FUNCTION_NAME_LENGTH + 32)),
+            "a".repeat(MAX_FUNCTION_NAME_LENGTH)
+        );
     }
 
     #[test]
     fn test_is_valid_function_name() {
         assert!(is_valid_function_name("hello-world"));
         assert!(is_valid_function_name("hello_world"));
+        assert!(is_valid_function_name(
+            &"a".repeat(MAX_FUNCTION_NAME_LENGTH + 1)
+        ));
         assert!(!is_valid_function_name("hello world"));
         assert!(!is_valid_function_name("hello@world"));
     }

crates/goose-provider-types/src/formats/openai_responses.rs

@@ -2157,6 +2157,32 @@ mod tests {
         assert_eq!(input[1]["name"], "_Review_Agent");
     }
 
+    #[test]
+    fn test_responses_request_limits_replayed_function_call_names() {
+        use crate::conversation::message::Message;
+
+        let messages = vec![Message::assistant().with_tool_request(
+            "call_long_name",
+            Ok(CallToolRequestParams::new("a".repeat(160))),
+        )];
+        let model_config = ModelConfig {
+            model_name: "gpt-5.5".to_string(),
+            context_limit: None,
+            temperature: None,
+            max_tokens: None,
+            toolshim: false,
+            toolshim_model: None,
+            request_params: None,
+            reasoning: None,
+            request_headers: None,
+        };
+
+        let result = create_responses_request(&model_config, "", &messages, &[]).unwrap();
+        let name = result["input"][0]["name"].as_str().unwrap();
+
+        assert_eq!(name.len(), 128);
+    }
+
     #[test]
     fn test_tool_request_error_emits_function_call_output() {
         use crate::conversation::message::Message;