TL;DR: Leave comments just for important design decisions. Don't explain the obvious!

Problems

• Maintainability

• Obsolete Documentation

• Readability

• Code and comments duplication.

Solutions

• Refactor methods.

• Rename methods to more declarative ones.

• Break methods into smaller and easier for understanding methods.

• If a comment describes what a method does, name the method with this description.

• comment on important design decisions only!

Examples

• Libraries

• Class Comments

• Method Comments

Sample Code

Wrong

/**
 * ChatBotConnectionHelper is used to create connection strings to
 * Bot Platform Use this class with getString() function to get 
 * connection string to the platform.
 */
class ChatBotConnectionHelper(
    var id: String
) {
    // Get Connection String from Chatbot
    fun getString(): String = TODO()
}

Right

class ChatBotConnectionSequenceGenerator(
    private val name: String
) {
    fun connectionSequence(): Unit = TODO()
}

Conclusion

Leave comments just for important design decisions. Don't comment on a method with a bad name, rename it. Code changes over time, while documentation rarely does, which causes your code to end up with outdated documentation at best, or wrong documentation at worst.

More info

• Refactoring Guru

• What is in a name

• Comments as a bad sign

• How to comment your code

Credits

• Code Smell 05 - Comment Abusers by Maxi Contieri