[UR] Improve wording consistency in specification

[martygrant]

Creating an issue for a point @frasercrmck raised in #17094:

Not for this PR but do you think there's an argument to write up some spec guidelines on wording, or perform a pass on the language?
I notice there's little consistency in how these descriptions are written: we've got X, Return a X, return X, Returns a X, and returns a X in the same enum.

Perhaps we should create some tasks to write some wording guidelines for the spec and take a pass through the project and update where necessary.