How the answer is reached
Two things decide it. The first is orientation: upright leans yes, reversed leans no. The second is the card itself, since some cards are obstructive whichever way up they land and some are not.
The Tower upright is not a yes. The Sun reversed is not a flat no. Combining the two gives five possible answers rather than two, and the middle one, unclear, is a real result rather than a failure.
What unclear actually means
When the card and its orientation pull against each other, the tool says so. In practice that almost always means the question was not really a yes-or-no question, and rephrasing it produces a much sharper reading.
Questions containing the word should are the usual culprit. The cards are considerably better at describing what is than at telling you what to do.
The limits worth stating
No tarot spread predicts events, and a yes-or-no draw is the format most likely to be mistaken for one. What it can do is surface your own reaction: the disappointment on seeing a no is frequently more informative than the card.
Anything with real consequences deserves better than a single card, and this spread is not the tool for it.
Rephrasing a question the cards can answer
The reliable move is to convert should into what. Instead of asking whether you should leave the job, ask what leaving would actually bring, and draw three cards rather than one. The answer stops being a verdict and starts being information.
Timing questions are the other common failure. Tarot has no calendar in it, and a card drawn on whether something happens this year is answering a question the deck cannot hold. For dated timing this site has transit and return calculators that compute real dates rather than suggesting them.
What this reading is and is not
The cards are drawn by a random number generator seeded once per reading. There is no server, no account and no record of your question; the whole draw is rebuilt from the number in the address bar, which is why the link reopens the same cards.
What a spread does well is give a structured way to look at a situation you already know something about. It is a prompt, not a source of information, and nothing here should be used in place of medical, legal or financial advice.
Questions people ask about this
Is a yes or no reading actually a prediction?
No. It is a convention about how to count one card, not information about what will happen. The convention is stated openly here so that you can see it is a rule rather than a revelation, and the useful part is usually your own reaction to the answer rather than the answer.
How is the answer counted?
Two things are added together. Orientation counts first, upright leaning yes and reversed leaning no, and then the card itself, since some cards are obstructive whichever way up they land and some are helpful. A helpful card upright gives an unambiguous yes, a difficult card reversed gives a no, and everything in between lands on leaning yes, leaning no, or unclear.
How many cards, and how long does it take?
One card, and about a minute. The single card is the point: there is no second card to soften it and no sequence to rearrange, so you are left with the answer and whatever you feel about it.
What does unclear mean?
It means the card and its orientation pull against each other, so the count lands in the middle. That is a real result rather than a failure, and in practice it almost always means the question was not really a yes-or-no question. Questions containing the word should are the usual culprit.
Can I save or share the answer?
Yes. The shuffle is a seeded random number generator and the reading rebuilds from its own link, so the same URL always shows the same card and the same count. That is handy if you want to look at it again once the feeling has worn off, since the second look is often more honest than the first.
When should I use a different spread?
Whenever the consequences are real. Convert should into what, ask what leaving the job would actually bring rather than whether to leave, and draw three cards instead. The answer stops being a verdict and starts being something you can think with.