user: Question: How many descriptions are there when the attribute is "ondragstart"?
Columns: ['Category', 'Type', 'Attribute', 'Description', 'Bubbles', 'Cancelable']
Types: ['text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['Mouse', 'dragstart', 'ondragstart', 'Fired on an element when a drag is started.', 'Yes', 'Yes']
SQL:

assistant: SELECT COUNT("Description") FROM "Table" WHERE "Attribute" = 'ondragstart';