Why is scannability important?

Text is an extremely useful communication medium. You’ll need it for your homepage, category pages, product detail pages, help page, and many more.

So it’s important to make your text scannable. If your product description is 200 words long, the average customer will not really read it in its entirety. They’ll mostly scan the description for important product attributes. It would be a disaster if they were to encounter a massive wall of text instead of easily scannable content.

Why are walls of text bad?

They are intimidating so most people don’t bother reading them.
They signal low-quality content such as rants so you definitely don’t want to be in that company.
They’re visually unappealing which discourages people from reading them.
They give the impression that your content is much longer than it actually is.
They lead to product abandonment, according to Baymard.

What to do with a wall of text

If you have a wall of text, you need to break it up.

During testing, we observed that if subjects came across product descriptions made up of large blocks of text with few or no bullets, they often felt overwhelmed and had difficulty finding relevant information. And when subjects encountered bullet lists with few or no blocks of text they were often left with unanswered questions about technical terms or features. In either case, the product description was judged by users to be insufficient and the product was often abandoned. (source)

Here are a few things you can do to make it visually appealing:

Use bulleted points or numbered lists. These are visually appealing and also give an idea of how many points someone can expect to read.
Bold important sentences or parts of sentences. Someone scanning will be more drawn to bolded sections in order to get the gist quickly. You should avoid bolding single words as they don’t give enough context to anyone who is just scanning.
Break up your text into paragraphs of around four lines each.
Use headings and subheadings to increase scannability.
Use images and illustrations to communicate more information and raise the visual appeal of your content.