The PuTTY agent can service both PuTTY clients and Microsoft OpenSSH clients, and it can do this without a service, nor does it need the implied administrative privileges to launch said service. That is a hands-down win.
The PuTTY clients can also accept raw passwords in several ways, by interactive prompt, by the -pw option on the command line (beware of exposure in task manager), and by the -pwfile option.
The latter above can be adapted to the .netrc format (used by Microsoft curl.exe and ftp.exe), which vastly expands authentication options.
So the question is why anyone bothers with Microsoft's ssh-agent.exe - it's quite limited.
The PuTTY agent can service both PuTTY clients and Microsoft OpenSSH clients, and it can do this without a service, nor does it need the implied administrative privileges to launch said service. That is a hands-down win.
The PuTTY clients can also accept raw passwords in several ways, by interactive prompt, by the -pw option on the command line (beware of exposure in task manager), and by the -pwfile option.
The latter above can be adapted to the .netrc format (used by Microsoft curl.exe and ftp.exe), which vastly expands authentication options.
So the question is why anyone bothers with Microsoft's ssh-agent.exe - it's quite limited.
Ditch it.