I am not well-read on this, but from what I have read it seems that it would be quite easy to spot the anti-Christ, as he will bring material comforts, rather than spiritual. My intuition is that it will play out that material comforts will successively be taken away, and we will be told we will get it back if only we do X. This process leads to worsening conditions until we are offered a choice - Christ of the last comfort.
I have found that the vast majority of people are oblivious to material vs. non-material arguments. It's like talking to them about COVID being a scam. They just don't respond. All people understand is - is health care getting better, are my wages going up ... are they or their bedfellows getting a good material deal. That is almost the entirety of modern debate.
We will know him by his fruits, yes. If a new global world leader promises a worldly kingdom and material riches in exchange for absolute allegiance (not to mention the fact he will be Jewish), then we should know that something is very wrong.
But my point was more to do with the general appearance/countenance of the antichrist, as many tacitly assume he will manifest as the typical red-horned devil, but from what I understand, to the world he will appear beautiful, radiant, and angelic (at least for a time), which will be the most difficult dilemma for any discerning Christian in those final days.
I get the impression that he will have an irresistible charisma, so that even if we might suspect something of this strange otherworldly man, that his words could win us over if we're not careful.
I've even heard some saints say quite sternly, that when he arrives, no one should even dare to look at the antichrist's face, fearing that one may be tempted by only a simple glance. This is identical advice towards how we deal with the passions, especially lust, that when we find ourselves tempted or feel passions rising within us, instead of deal with them directly, we should run like a small child to Christ, for our protection, as we cannot do it on our own.
So it will be like dealing with the most beautiful person we have ever seen, a completely irresistible personality and someone with the most magnetic charisma -- the charm of the devil, no less. That's why his sudden appearance from complete obscurity will make it all the more dramatic and attractive for people, so it won't be baby X. But the 'spirit of antichrist' has been working tirelessly ever since the martyrdom of Tsar Nicholas II over a hundred years ago, and numerous 'types' have arisen since then, from Stalin all the way down to Musk, so these figures are warning signs at the least and a reminder to stay vigilant.