What is it about your tool that you need for the job? Is your tool specifically designed for your (type of) job? What trade-offs are you making with that tool versus other tools? Did you consider the long-term implications of your choice of tool? What if you wish to extend your job? Is your tool well-maintained? What if a customer comes back with questions about your job after a few years? Is it possible that more people will work on your job? Will they need to learn your tool? Will you still be happy about your choice of tool? (etc, etc, etc)
Programming is partly a creative pursuit. Thus, it helps if one enjoys using the tool you need for the job.