No information is lost, still available on hover.
The comment itself is not helpful to users and would be presented on every validation error

Moved repeat info to *Notes*, which should come last https://numpydoc.readthedocs.io/en/latest/format.html#notes
Removed redundant *Returns*
Minor changes to improve readability

Saves 2 lines, identical result, maybe faster due to not allocating an intermediate dict

All `...ChannelMixin` already use this form. Saves 2 lines

Saves only 1 line, but collapses the dict comp.
The `:=` expr doesn't reduce lines, but does reduce characters

Saves 2 lines, avoids repeating the 3 kwargs - but allows modified `context`

…-traceback

As with the change to `SchemaValidationError`, the information is available in a docstring if needed.
But no longer is displayed to the user on a validation error

Removes 5 lines.
Has the additional benefit of replacing an identical block in `SchemaBase.validate_property`.
Therefore reduces the maintenance burden of keeping comments in sync

…copy)`

The call to `.to_dict`, and 3 line comment also appeared in the traceback for validation errors on `ChartType`s.
This removes the need for the comment and type ignore that it is describing.
See vega#3480 for more info on the introduction of `_top_schema_base`

Discovered during debugging that the rhs always evaluated as `type`, which was not intentional

Just to keep things consistent

Should achieve greater consistency across the public API

vega#3530 (comment)

vega#3530 (comment)