feat: tool error classification — retryable vs permanent (#752) (#773)

Co-authored-by: Alexander Whitestone <alexander@alexanderwhitestone.com>
Co-committed-by: Alexander Whitestone <alexander@alexanderwhitestone.com>

tests/test_error_classifier.py

@@ -0,0 +1,55 @@
+"""
+Tests for error classification (#752).
+"""
+
+import pytest
+from tools.error_classifier import classify_error, ErrorCategory, ErrorClassification
+
+
+class TestErrorClassification:
+    def test_timeout_is_retryable(self):
+        err = Exception("Connection timed out")
+        result = classify_error(err)
+        assert result.category == ErrorCategory.RETRYABLE
+        assert result.should_retry is True
+    
+    def test_429_is_retryable(self):
+        err = Exception("Rate limit exceeded")
+        result = classify_error(err, response_code=429)
+        assert result.category == ErrorCategory.RETRYABLE
+        assert result.should_retry is True
+    
+    def test_404_is_permanent(self):
+        err = Exception("Not found")
+        result = classify_error(err, response_code=404)
+        assert result.category == ErrorCategory.PERMANENT
+        assert result.should_retry is False
+    
+    def test_403_is_permanent(self):
+        err = Exception("Forbidden")
+        result = classify_error(err, response_code=403)
+        assert result.category == ErrorCategory.PERMANENT
+        assert result.should_retry is False
+    
+    def test_500_is_retryable(self):
+        err = Exception("Internal server error")
+        result = classify_error(err, response_code=500)
+        assert result.category == ErrorCategory.RETRYABLE
+        assert result.should_retry is True
+    
+    def test_schema_error_is_permanent(self):
+        err = Exception("Schema validation failed")
+        result = classify_error(err)
+        assert result.category == ErrorCategory.PERMANENT
+        assert result.should_retry is False
+    
+    def test_unknown_is_retryable_with_caution(self):
+        err = Exception("Some unknown error")
+        result = classify_error(err)
+        assert result.category == ErrorCategory.UNKNOWN
+        assert result.should_retry is True
+        assert result.max_retries == 1
+
+
+if __name__ == "__main__":
+    pytest.main([__file__])