Begin with a strong hook that will intrigue the agent so that he requests your script. Take the leap with this powerful tool, because it has the power to pay off in the only way that counts — getting someone to want to read your material.
Include a self-addressed-stamped-envelop SASE for the editor's reply. I am only saying that if your concept doesn't query well, then either: you're not getting through to people how wonderful your idea is, and you need to rewrite your query, or people don't think it's that wonderful an idea, and you need a better idea.
Please let me know if I can send you the pilot, and thanks for your time and consideration. A single sentence is highly preferred.
You can also find loglines for any existing movies on IMDB. I understand that you love your story and want to tell us all about it, because to know it is to love it.
They may ask for a synopsis.