Run ssh-agent on shared hosting plan

I'm trying to run "git clone..." against my BitBucket repository. I need to start ssh-agent, then run ssh-add to add my private key. The output below seems to suggest that I can not run ssh-agent on my shared hosting plan? Please confirm.

$ eval ssh-agent -s
SSH_AUTH_SOCK=/tmp/ssh-SFTj141461/agent.141461; export SSH_AUTH_SOCK;
SSH_AGENT_PID=141463; export SSH_AGENT_PID;
echo Agent pid 141463;

$ ssh-add ~/.ssh/<private_key_file>

Could not open a connection to your authentication agent.