Bullet points help you to sell features and benefits of your product. They are descriptive text about specific aspects of a product, which appear on the detail page. Up to five bullet points can be included for each product.
Some bullet points are so long that customers have to click a more button to see all of them. Some bullet points are stuffed with keywords and are not easy to read. Some bullet points are poorly written.
It is better to keep bullet points clear and concise. A general piece of advice is to keep your bullet points under 1,000 characters in total, i.e. for all five bullets, not per bullet. Being less than 1,000 characters improves their readability. If bullet points are indexed for your product, being shorter than 1,000 characters improves discoverability of content in the bullet points.
Well-written bullet points will naturally contain keywords, but the first priority should be to communicate clearly and help customers make a buying decision. One approach is to start a bullet point with a feature and then state the benefit(s) of that feature.
For example, '50-minute run-time trims up to 1,200 square feet per charge' states that the feature of a 50-minute run-time delivers the benefit of being able to trim up to 1,200 square feet per charge.
Bullet points always appear in full on product detail pages. However, not all content is discoverable because bullet points are not always indexed by the Amazon shopping algorithm.
The Amazon shopping algorithm is constantly evolving. Even if the algorithm does not index all bullet points or changes how it indexes bullet points, there will always be value in making your listings as good as they can be.