Describe What You See
For visual bugs, describe the exact symptom: what overflows, what's misaligned, what's hidden. Include the viewport or device size where it breaks. 'It looks wrong on mobile' is useless. 'The sidebar overflows on screens below 768px causing a horizontal scrollbar' gives Claude a clear target.
Where you'll practice this
One Promptles scenario teaches this principle directly.
The Layout Bug
Your app's sidebar navigation works fine on desktop, but on screens narrower than 768px it overflows its container: the sidebar pushes content off screen and causes a horizontal scrollbar. The sidebar is defined in `Sidebar.tsx` with styles in `Sidebar.css`. The design spec says…