Hi,
What type of credentials are you using? It can be either environment variables or in the credentials file.
The credentials files should work as it is based on the owner used to run the job and should be in a set location.
*nix: ~/.aws/credentials
Windows: %UserProfile%\.aws
If you are using environment variables, you may need to source your user profile if the agent is not configured to do so.
I have jobs that use the aws s3 and other services and run just fine. I have done both type of credentials as well.
Regards,
Mike