Name the tool and provide a small safe input that produces the confusing result. Show the output you expected and the one you received, including the exact error text if available. For a visual bug, add browser, device, zoom level, and a redacted screenshot.
Run the example once more before posting so you know whether it is repeatable. Replace real account details and private files with synthetic data, but preserve the feature that triggers the issue. If a formatter changes a value rather than just its appearance, say which field changed.
A focused before-and-after example gives others a concrete test.