Sammy, welcome to your Anova Community. SV cooking is unlike any other cooking technique you've previously used. Lower cooking temperatures along with longer times are the most significant differences your are going to encounter, but there are others. Please excuse my overly long response to your very short question, but there's a lot to tell you about SV cooking even with that small roast.
Another challenging difference you will encounter is using a product's thickness to establish the minimum heating time required in the water bath. In SV cooking once you've paid for the meat it's weight doesn't matter any more, but that's only for tender cuts of meat and poultry. So let's move along.
The generally accepted internal cooked temperature for Medium-Rare meat is 130F / 55C. I'll leave the adjustment of a tad up to you. FYI, Medium doneness is 140F / 60C. Your choice of temperature will be the temperature setting on your Anova. What you set is what you will get in the meat. Eventually.
For any cooking time in excess of 4 hours i use a minimum temperature of 132F / 55.5C for food safety reasons.
Your sirloin tip roast is cut from the top of the rear leg, a very well exercised muscle that is going to need a lot of cooking to become enjoyably tender. I use somewhere between 10 and 24 hours as a basic cooking time for tough meat. The longer time would be appropriate for the usual grocery store USDA Coice or Select beef. If you've gone upscale trust your best judgement as to how much shorter the time you use based on breed of cattle, grade, and aging.
One last item, do yourself a big favour and starting with this roast record the details of all your SV cooking.
Here's what i use:
Specific type or cut of meat.
Desired degree of doneness / cook temperature.
Thawed or frozen?
Planned / actual cook time.
Cook-serve / cook-chill / cook freeze?
Comments on outcome.
If you are seriously interested in precision SV cooking the best guide i know of is the following site: