The immunity tag info says
Immunity to civil or criminal liability conferred to an individual by virtue of an office.
However, this is a group of specific types of immunity, including parliamentary immunity and judicial immunity.
We already have a tag separately for diplomatic immunity, diplomatic-immunity which is also strictly a subset of the questions that are covered by the above description, and therefore by that tag also.
There are many other types of immunity that have nothing to do with holders of an office, and for which we have questions already on the site that are not tagged appropriately (nobody has created the specific tag, and the general tag cannot be used according to its description, so either it is not tagged or uses some related tag like liability).
The solution requires three things:
Creation of new tag(s) specific to the types of immunity featured in questions which currently are tagged with immunity. Judicial immunity for judges and lawyers, parliamentary immunity (potentially with related tag for parliamentary privilege) and similar for elected officials, sovereign immunity for both sovereign states and heads of government not already covered by other immunity.
Retagging of those questions with the appropriate specific type.
Editing of the tag info to an appropriate general description, and directions to use one of the more specific tags if this is available.
A general immunity tag info should read
For questions about immunity from civil or criminal liability conferred on a natural or legal person.
Separately, questions where a further immunity is a topic and are not already tagged as above, need tags created for them.