When you are in the process of recruiting salespeople, there are a number of KPI's you can track to reveal how effective you are at finding, attracting, assessing, screening, interviewing, selecting, hiring, on boarding and retaining great salespeople. Yes, each of the topics just mentioned are pieces of the sales recruiting process and they can all be tweaked, improved and refined until you get it just right. It's sort of like cooking with the only difference being that I can't cook (grilling doesn't count) but I can sure find the right salespeople.
Your candidate pool is comprised of the quantity and quality of candidates who respond to your online posting. If you are not happy with either the quality or quantity of your pool, then your ad, title or job site settings are to blame. Tweak those as you would your recipe ingredients. In about 9 out of 10 cases that I've seen, the ad is to blame. Describe the candidate you need; not the darn opportunity or company!
If you aren't happy with the number of candidates who are getting recommended by your assessment, your assessment criteria could be the reason. However, if you remove or reduce some criteria you'll be compromising on the quality of the candidates. Once again, it is more likely that you need to tweak your ad. See above.
If you aren't happy with the candidates you speak with by phone, you can add criteria to your assessment and you'll simply have fewer candidates that get recommended. Then you won't waste your time talking to frauds, wanna be's, and morons!
If you find that the candidates who make it all the way through to your first interview aren't the quality you were hoping for, your phone screening call is probably to blame. You probably aren't being tough enough with your questions or your scoring is too generous. You must be fast and firm on that phone call!
Finally, if you aren't happy with the salespeople you are selecting, you can look in the mirror. Ask yourself to what degree you are putting your likes and dislikes ahead of the data. The data never lies but your eyes will tell you you're hungry right after you eat! There is a place for gut feel, but it should never take place at selection time when following your gut means overruling the data.