Every package needs a description, but why write a low-effort one when you can write a great one!

Here is some info which you should include in your description:

Tweaks:

• Describe what your tweak does
• List what applications it works in (if applicable) 
• Explain your refund policy
• Device support (Ideally, all devices should be supported, if this is the case you don’t need to mention it)

Themes:

• List how many icons are in the theme (this number should be maintained every update)
• What your inspiration was for this theme
• Explain your refund policy
• A way of contacting you for icon requests such as email, Twitter, or Discord server

You should not add info that is already shown, such as:

• iOS version support
• Pricing
• Support contact info. You should make sure this contact info is set in the developer portal.
• Changelog - This belongs in the dedicated changelog section.