The only way, and we do mean the only way to tell if your keyword is working is to check your Etsy Shop Stats to see if you're getting found for it. Etsy agrees in their The Ultimate Guide to Etsy Search.
Avoid this common waste of time!
We need to address a far too common practice (it should have been stopped long ago). You've probably witnessed someone asking around on social media where their listing shows in search for other people. Don't fall for this trap.
In their guide, Etsy specifically discourages trying to see where your item shows up in search because it simply won't work (even on a fresh browser or a different device). It isn't what other shoppers are seeing so don't waste your time on it.
Etsy's machine learning (CSR and personalized search) is experimenting with search results from device to device and person to person way too much for checking rank to be accurate. It's a bigger picture than we'll ever see from just asking 50 people where we (or if we) show up.
What should I do instead?
Go into your Etsy Shop Stats and look at what keywords are actually being used to find your listings. If you're picking good keywords and applying them correctly, you should see your Marmalead keywords popping up in there! You see, it doesn't matter which position you're in at a given moment in time, it matters if Etsy is actually showing your listing to real shoppers.
Take a look at your most-visited listings and the search terms bringing them there. These are keywords that are working well for you!
Then head over to your least-visited listings and compare their tags to the most-visited. This can give you insight to what is and isn't working. One solution could be to add some of the tags that are working to your lower performing listings. BUT you certainly don't want to fill all your listings with the same tags because you'll miss out on so many opportunities. So make sure you balance that with a refresh of the other under performing tags.
Tips for Success
Etsy recommends to diversify the tags you're using. They want to get your listings in front of as many different shoppers as possible and the only way that can happen is if you experiment with a whole bunch of keywords.
Target long tail keywords, Marmalead tells you whether a keyword is long tail and if real shoppers are searching and engaging with it!
Keep checking your stats and working on replacing underperforming keywords. Especially consider that with Marmalead's Seasonality and Forecasting, you can stay ahead of keyword slumps.
Keep an eye on your listing Grades in Marmalead. They're designed to help you maximize your visibility in search by following Etsy guidance.
Do not fall into the "set it and forget it" trap. Keep your listings stocked with the best keywords all year long.