> Additionally, I want to tyty to have better and more descriptive error messages than tsc's. Isn't this nice?: (https://zackoverflow.dev/tyty-errors.jpeg)

Actually, no. It looks fancy, sure, but error messages aren't there to be pretty, but to be usable.

1. I expect the first line of an error to give me a succinct, yet precise description of the problem.

     Error: Incompatible types

It would never be possible for me to fix code based on this alone. Contrast with Python:

    TypeError: unsupported operand type(s) for +: 'int' and 'str'.

I'm sure you can easily figure out what code triggered the above error just based on itself.

At minimum, the first line should say which types are incompatible:

    Error: Incompatible types MyType and MyType2

2. How am I supposed to read the

    Because of this type annotation

part? Is it

    MyFn has the type: X
    Because of this type annotation

or

    Because of this type annotation
    MyFn has the type: X

?

To fix, include guiding punctuation:

    MyFn has the type: X ...
    ... Because of this type annotation

or

    Because of this type annotation ... 
    ... MyFn has the type: X.

Actually, it looks like it's neither and I'm somehow supposed to read it as

    Error: Incompatible types, because of this type annotation

... which is impossible to figure out without context. I should be able to read the error message top-down or bottom-up.

To sum up, error messages are there for the programmer to be able to quickly get the gist of what happened, so they should be as obvious as possible. Check out Rust's errors for some inspiration: https://blog.rust-lang.org/2016/08/10/Shape-of-errors-to-com...