Judiciousness and fairness in the use of words that are arguably extraneous to a clue is a worthy topic for creators and solvers.  From my point of view, some latitude must be granted to designers when it comes to the standards for connectors.

Many cryptic clues contain words that, if you want to be technical, don’t need to be there and often serve mostly to confuse.  Yet, without really injuring the sense of the clue, many of these words lend a flow — a rhythm — to the clue, making it more palatable and easier to read.  I think we can all agree that tossing in superfluous words that have no other reason for being there other than to confuse is not a preferable, or fair, approach to drafting clues.  On the other hand, while creators strive to be reasonably fair — and the best extremely fair — some leeway, some flexibility, for the sake of readability of clues, should be tolerated.  “Padding” is a pejorative term sometimes used to describe extraneous words that unfairly confuse a clue.

Keep in mind, several types of clues, for instance, double definition, normally do not contain linking words.

Here are some linking words that convention suggests may immediately precede the definition/answer of a clue — these linking words, therefore, follow the wordplay:

is, for, giving, yielding, becoming, leads to, lead to, offering, to get, getting, becomes, being, was, produces, makes, delivers, constitutes, creates, is considered, seems like

And, some linking words that follow the definition/answer (thereby preceding the wordplay):

derived from, from, is, given by, can be, derived from, could be, might have been, is considered, might be, comes from

In many cryptics, “of,” “at,”  “with” and “on” are also used as connectors.  “A,” “an” and “the” work in some situations too.