BUG #16726: Invalid input syntax is not a useful error message

The following bug has been logged on the website:

Bug reference: 16726
Logged by: No useful error message
Email address: nozdrum(at)gmx(dot)de
PostgreSQL version: 13.0
Operating system: Linux
Description:

I tried to update the uuid-value of a user with a uuid-literal. Since the
documentation on this is so useless:
https://www.postgresql.org/docs/13/datatype-uuid.html I had to try and
finally give up.

Example-query i tried:
update users set
some_uuid_field = 'dec3d6c4-c32e-45c6-1eae3df44fbf'
where
id = 5

I tried ( as is suggested in your documentation) to set with and without
sorounding single quotation mark and with and without braces. I always got
the same useless error message
`ERROR: invalid input syntax for type uuid:
"dec3d6c4-c32e-45c6-1eae3df44fbf"`

I also tried curly braces ( as suggested by your awful documentation ), but
this just leads to
`syntax error at or near "{"`

What I want:
a) That your documentation tells me the syntax for this
b) That your error messages FOR ONCE are not useless and tell me the
expected syntax, you are wasting millions of hours of developer time and
human life, because you can not be asked to make useful error messages.