voice dictation – How can I test vocal commands?

I’ve defined vocal commands using System Preferences ﹥ Accessibility ﹥ Dictation (macOS 10.14.4). Sometimes they work, sometimes they don’t. I guess recognition rate is not 100%, and I’d like to improve it, for instance by chosing different wording. “Make it so” may be better recognized than “Engage”. How can I get feedback on recognition rate?