For projects that are expected to grow, it is a good idea add comments your Gemfile
. That way, even in large setups you will still know what each gem does even if the name is not self-explanatory and you added it 2 years ago.
This can also help you to remember why you chose a certain version and consequently re-evaluate the version requirement later on.
Examples:
# temporary downgrade for TeamCity
gem 'rake', '~> 10.5.0'
# To upload invoicing information to payment provider
gem 'net-sftp'