When adding github or Bitbucket account to SourceTree and letting source tree to generate ssh key, the generated configuration added in ~/.ssh/config have incorrect value for Host where it put name of ssh key instead of service domain e.g. bitbucket.org. It results that key have to be added to ssh agent after every reboot manually. 

Mentioned:

https://community.atlassian.com/t5/Sourcetree-questions/Permission-denied-publickey-after-restart/qaq-p/590249

Current format of ssh configuration:

1. — Sourcetree Generated —

Host ssh_key_name

        HostName bitbucket.org

        User user_name

        PreferredAuthentications publickey

        IdentityFile /Users/user/.ssh/ssh_key_name

        UseKeychain yes

        AddKeysToAgent yes

#----------------------------

working format:

1. — Sourcetree Generated —

Host bitbucket.org

        HostName bitbucket.org

        User user_name

        PreferredAuthentications publickey

        IdentityFile /Users/user/.ssh/ssh_key_name

        UseKeychain yes

        AddKeysToAgent yes

#----------------------------