fix: pass message to ToolRetryError parent class

ToolRetryError was not passing a message to Exception.__init__(),
causing str(error) to return an empty string. This breaks error
monitoring tools like Sentry that rely on str(exception) to display
error messages.

The fix passes tool_retry.model_response() to the parent class,
ensuring the error message is properly accessible via str(error)
and error.args.

Author: Work

pydantic_ai_slim/pydantic_ai/exceptions.py

@@ -188,7 +188,7 @@ class ToolRetryError(Exception):
 
     def __init__(self, tool_retry: RetryPromptPart):
         self.tool_retry = tool_retry
-        super().__init__()
+        super().__init__(tool_retry.model_response())
 
 
 class IncompleteToolCall(UnexpectedModelBehavior):

tests/test_exceptions.py

@@ -13,10 +13,12 @@
     IncompleteToolCall,
     ModelAPIError,
     ModelHTTPError,
+    ToolRetryError,
     UnexpectedModelBehavior,
     UsageLimitExceeded,
     UserError,
 )
+from pydantic_ai.messages import RetryPromptPart
 
 
 @pytest.mark.parametrize(
@@ -32,6 +34,7 @@
         lambda: ModelAPIError('model', 'test message'),
         lambda: ModelHTTPError(500, 'model'),
         lambda: IncompleteToolCall('test'),
+        lambda: ToolRetryError(RetryPromptPart(content='test', tool_name='test')),
     ],
     ids=[
         'ModelRetry',
@@ -44,6 +47,7 @@
         'ModelAPIError',
         'ModelHTTPError',
         'IncompleteToolCall',
+        'ToolRetryError',
     ],
 )
 def test_exceptions_hashable(exc_factory: Callable[[], Any]):
@@ -59,3 +63,11 @@ def test_exceptions_hashable(exc_factory: Callable[[], Any]):
 
     assert exc in s
     assert d[exc] == 'value'
+
+
+def test_tool_retry_error_str():
+    """Test that ToolRetryError has a meaningful string representation."""
+
+    part = RetryPromptPart(content='Invalid query syntax', tool_name='sql_query')
+    error = ToolRetryError(part)
+    assert 'Invalid query syntax' in str(error)