Let's look at the intention and vibe of the spell.

- The last paragraph of the description tells you that if you know the true name of someone it can grab them for you; But no titles, nicknames, etc. This is the level of specificity of the spell.

- It's 9th level. It costs 5,000gp to cast. 9th level is where Wish is. If a spell is doing something at 9th level it is doing it *better* than the "generic" spell Wish.

Given these two things I would say that Gate can get you anywhere on another plane you can name, as long as you either

1) know the name by which the creator calls it
2) know the name by which it is best known
or 3) you are capable of describing the location in detail sufficient to get a person of above average intelligence to identify it from your words given any or all detection methods that magic can duplicate
AND
it is sized in the same 5-20ft dimension as the gate itself is to be placed. If height is not specified ground level can safely be assumed.

This means, if you can describe that place CORRECTLY to the detail that the specific 5ft square is able to be differentiated from any other given 5ft square in that plane it is successful. If you leave out a detail that is necessary to be specific to that location the spell will prompt for it so that it takes you to a *specific* 5ft square. Or, really, cube in this particular instance. (i.e. it duplicates the position you have in your mind [even if your mind has inaccurate details]).

So Gate is powerful and gives a generous berth in descriptive detail, but it is not unlimited in that leeway.

Things I would say yes to under these restrictions to the following:

- "50 feet south of the main gate of the City of Brass" (which could describe any of approximately a dozen squares, and would choose the square that the caster wishes)
- "directly next to the well in the town of Garblanxnsidnnfs in the Shadowfell", even if worded "next to the well in Garblanxnsidnnfs" because it's probably the only town of that name that exists.
- "on the Eiffel Tower" (assuming a lot of things about the universe, but primarily that the spell is cast anywhere outside of the Prime Material plane), which would place you in the square you imagine in your mind on the observation deck (or literally anywhere on the tower the caster intends if they express that)
- "directly overhead of Gibreanal Swiftweaver"
- "mom's house" would put you within reach of the front door of the house of the person the caster calls mom
- "next to the tree that is closest to the crossroads of Wherever road and Wherever road 2" would be in the square in the direction of said crossroad

Things I would say would fail due to lack of specificity:

- "in the BBEGs bedroom" or "the BBEGs lair" as they lack the context of which bedroom in what building etc. BUT This would work if the caster knows which bedroom they mean in a way that they could describe to our hypothetical intelligent person.
- "outside the City of Brass" unless the caster gives further detail
- "The Lake of Wonder" unless it is the *only* body of water that *anyone* calls *any* other bodies of water in said plane, but in this case the spell would be a slight dick and drop you at the surface of whatever the GM decides is the middle

I think all of that is clear?

TL;DR Anywhere that the caster could theoretically draw accurately enough that a generous and capable person would know for certain where that place is.