Hi @Cris2
You can write specific tooltip for lookup using below code:
$( document ).ready(function() {
$($("#regardingobjectid").next().next()).find(".btn.btn-default.launchentitylookup").attr("data-original-title","Your tooltip");
$($("#regardingobjectid").next().next()).find(".btn.btn-default.launchentitylookup").attr("title","Your tooltip");
$($("#regardingobjectid").next().next()).find(".btn.btn-default.launchentitylookup").attr("aria-label","Your tooltip");
});
Please replace regardingobjectid text with your lookup field logical name.
Let me know if there is any issue.
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