What is the test for a monetary sanction against a party or attorney who unsuccessfully opposes a motion to compel further responses to interrogatories?

The Civil Discovery Act states that the court "shall impose a monetary sanction" against a party or attorney who unsuccessfully opposes a motion to compel further responses to interrogatories, "unless it finds that the one subject to the sanction acted with substantial justification or that other circumstances make the imposition of the sanction unjust." ( 2030.300, subd. (d).) Among the authorized reasons for imposing sanctions are: making, without substantial justification, an unmeritorious objection to discovery; making an evasive response to discovery; disobeying a court order to provide discovery; or unsuccessfully opposing a motion to compel. ( 2023.010.) The wording of the statute does not entitle a party "to one free refusal to serve further responses before a monetary sanction can be imposed. On the contrary, the plain language of the statute requires the trial court to impose a monetary sanction even for the first offense." (Parker v. Wolters Kluwer United States, Inc. (2007) 149 Cal.App.4th 285, 294.)