One of the reasons I initially pushed back on the creation of a JSON Schema for V3 is because I feared that people would try to use it as a document validator. However, I was convinced by other TSC members that there were valid uses of a schema beyond validation.
annotation meta: may need new tag: fear would be used for ... valid uses for it beyond ...
I'd also love to see a JSON schema along with the specification. I don't really trust myself to be able to accurately read the spec in its entirely, so for 2.0 I fell back heavily on using the included schemas to verify that what I'm generating is actually intelligible (and it worked, they caught many problems).
URI::MailTo::EMAIL_REGEXP
First time I've seen someone create a validator by simply matching against URI::MailTo::EMAIL_REGEXP from std lib. More often you see people copying and pasting some really long regex that they don't understand and is probably not loose enough. It's much better, though, to simply reuse a standard one from a library — by reference, rather than copying and pasting!!
To verify that your structured data is correct, many platforms provide validation tools. In this tutorial, we'll validate our structured data with the Google Structured Data Validation Tool.