diff --git a/web/src/app/app/settings/inbox-tagging/page.tsx b/web/src/app/app/settings/inbox-tagging/page.tsx
index 639501721..237a86c98 100644
--- a/web/src/app/app/settings/inbox-tagging/page.tsx
+++ b/web/src/app/app/settings/inbox-tagging/page.tsx
@@ -25,11 +25,11 @@ import {
     StatStrip,
 } from "@/components/layout/Page";
 import { NoAccess } from "@/components/layout/NoAccess";
+import { TagMeaningTooltip } from "@/components/ui/tag-meaning-tooltip";
 import { usePermission } from "@/hooks/usePermission";
 import useInboxTagReview from "@/lib/api/hooks/app/inboxtag/useInboxTagReview";
 import type { InboxTagRow } from "@/lib/api/models/app/inboxtag/InboxTagReview";
 import { cn } from "@/lib/utils";
-import { tagMeaning } from "@/lib/unibox/tagMeanings";
 
 const PRIORITY_TONE: Record<string, string> = {
     now: "bg-rose-50 text-rose-700",
@@ -83,13 +83,11 @@ function Row({ r }: { r: InboxTagRow }) {
                         <span className="text-[11.5px] text-slate-400">no labels</span>
                     ) : (
                         r.labels.map((l) => (
-                            <span
-                                key={l}
-                                title={tagMeaning(l) || l}
-                                className="px-1.5 rounded bg-slate-100 text-slate-700 text-[11px] cursor-help"
-                            >
-                                {l}
-                            </span>
+                            <TagMeaningTooltip key={l} title={l}>
+                                <span className="px-1.5 rounded bg-slate-100 text-slate-700 text-[11px] cursor-help">
+                                    {l}
+                                </span>
+                            </TagMeaningTooltip>
                         ))
                     )}
                 </div>
diff --git a/web/src/components/app/contacts/CategoryPicker.tsx b/web/src/components/app/contacts/CategoryPicker.tsx
index 8db605530..aa4fef97a 100644
--- a/web/src/components/app/contacts/CategoryPicker.tsx
+++ b/web/src/components/app/contacts/CategoryPicker.tsx
@@ -25,7 +25,7 @@ import useFlipPlacement from "@/hooks/useFlipPlacement";
 import clippedTitle from "@/lib/helper/clippedTitle";
 import useCreateCategory from "@/lib/api/hooks/app/categories/useCreateCategory";
 import type Category from "@/lib/api/models/app/Category";
-import { tagMeaning } from "@/lib/unibox/tagMeanings";
+import { TagMeaningTooltip } from "@/components/ui/tag-meaning-tooltip";
 
 interface Props {
     // Selected ids — kept as ids so the consumer can store them in the
@@ -225,46 +225,41 @@ export function CategoryChip({
     onRemove?: () => void;
     compact?: boolean;
 }) {
-    // Automatic labels carry their meaning on hover. A chip reading "going-cold"
-    // is only useful to somebody who already knows the taxonomy, and nobody
-    // does on the first day. A label the workspace made itself needs no gloss,
-    // so it gets the plain title.
-    const meaning = tagMeaning(category.title);
-
     return (
-        <span
-            title={meaning || category.title}
-            className={`inline-flex items-center gap-1 min-w-0 ${compact ? "h-4 pl-1 pr-1 text-[10px]" : "h-5 pl-1.5 pr-1 text-[11px]"} rounded font-medium`}
-            style={{
-                backgroundColor: hexToRgba(category.color, 0.12),
-                color: category.color,
-                border: `1px solid ${hexToRgba(category.color, 0.25)}`,
-            }}
-        >
+        <TagMeaningTooltip title={category.title}>
             <span
-                className={`${compact ? "size-1.5" : "size-2"} rounded-full shrink-0`}
-                style={{ backgroundColor: category.color }}
-            />
-            <span
-                className="truncate min-w-0 max-w-[72px] md:max-w-none"
-                {...clippedTitle}
+                className={`inline-flex items-center gap-1 min-w-0 ${compact ? "h-4 pl-1 pr-1 text-[10px]" : "h-5 pl-1.5 pr-1 text-[11px]"} rounded font-medium`}
+                style={{
+                    backgroundColor: hexToRgba(category.color, 0.12),
+                    color: category.color,
+                    border: `1px solid ${hexToRgba(category.color, 0.25)}`,
+                }}
             >
-                {category.title}
-            </span>
-            {onRemove && (
-                <button
-                    type="button"
-                    onClick={(e) => {
-                        e.stopPropagation();
-                        onRemove();
-                    }}
-                    className="opacity-70 hover:opacity-100"
-                    aria-label={`Remove ${category.title}`}
+                <span
+                    className={`${compact ? "size-1.5" : "size-2"} rounded-full shrink-0`}
+                    style={{ backgroundColor: category.color }}
+                />
+                <span
+                    className="truncate min-w-0 max-w-[72px] md:max-w-none"
+                    {...clippedTitle}
                 >
-                    <XIcon className="w-2.5 h-2.5" />
-                </button>
-            )}
-        </span>
+                    {category.title}
+                </span>
+                {onRemove && (
+                    <button
+                        type="button"
+                        onClick={(e) => {
+                            e.stopPropagation();
+                            onRemove();
+                        }}
+                        className="opacity-70 hover:opacity-100"
+                        aria-label={`Remove ${category.title}`}
+                    >
+                        <XIcon className="w-2.5 h-2.5" />
+                    </button>
+                )}
+            </span>
+        </TagMeaningTooltip>
     );
 }
 
diff --git a/web/src/components/app/unibox/ScopeRail.tsx b/web/src/components/app/unibox/ScopeRail.tsx
index c8684c839..de510e321 100644
--- a/web/src/components/app/unibox/ScopeRail.tsx
+++ b/web/src/components/app/unibox/ScopeRail.tsx
@@ -47,7 +47,8 @@ import {
   PopoverMenuTrigger,
 } from "@/components/ui/popover-menu";
 import type { UniboxFolder } from "@/lib/api/models/app/unibox/UniboxSearch";
-import { tagMeaning } from "@/lib/unibox/tagMeanings";
+import { TagMeaningTooltip } from "@/components/ui/tag-meaning-tooltip";
+import { isAutomaticTag } from "@/lib/unibox/tagMeanings";
 
 export type UniboxScope =
   | { kind: "all" }
@@ -246,16 +247,17 @@ export function ScopeRail({ scope, onChange }: ScopeRailProps) {
           searchPlaceholder="Filter labels"
           getSearchKey={(c) => c.title}
           renderItem={(c) => (
-            <Item
-              key={c.id}
-              icon={<Dot color={c.color} />}
-              label={c.title}
-              title={tagMeaning(c.title) || undefined}
-              count={c.unread || c.total || undefined}
-              accent={c.unread > 0}
-              active={active === `category:${c.id}`}
-              onClick={() => onChange({ kind: "category", categoryId: c.id })}
-            />
+            <TagMeaningTooltip key={c.id} title={c.title}>
+              <Item
+                icon={<Dot color={c.color} />}
+                label={c.title}
+                hideNativeTitle={isAutomaticTag(c.title)}
+                count={c.unread || c.total || undefined}
+                accent={c.unread > 0}
+                active={active === `category:${c.id}`}
+                onClick={() => onChange({ kind: "category", categoryId: c.id })}
+              />
+            </TagMeaningTooltip>
           )}
         />
       )}
@@ -547,7 +549,7 @@ function FolderItem({
 function Item({
   icon,
   label,
-  title,
+  hideNativeTitle,
   count,
   accent,
   active,
@@ -555,8 +557,7 @@ function Item({
 }: {
   icon: React.ReactNode;
   label: string;
-  /** Hover explanation, for the automatic labels whose names are not self-evident. */
-  title?: string;
+  hideNativeTitle?: boolean;
   count?: number;
   accent?: boolean;
   active?: boolean;
@@ -567,7 +568,7 @@ function Item({
       type="button"
       onClick={onClick}
       className={cn("group/item", ROW, active ? ROW_ACTIVE : ROW_IDLE)}
-      title={title || label}
+      title={hideNativeTitle ? undefined : label}
     >
       <span className={cn("shrink-0", active ? "text-slate-800" : "text-slate-400 group-hover/item:text-slate-600")}>
         {icon}
diff --git a/web/src/components/app/unibox/ThreadLabelMenu.tsx b/web/src/components/app/unibox/ThreadLabelMenu.tsx
index e157217aa..1faf1bb58 100644
--- a/web/src/components/app/unibox/ThreadLabelMenu.tsx
+++ b/web/src/components/app/unibox/ThreadLabelMenu.tsx
@@ -19,7 +19,7 @@ import { useUserProfile } from "@/hooks/context/user";
 import useCreateCategory from "@/lib/api/hooks/app/categories/useCreateCategory";
 import useThreadLabels from "@/lib/api/hooks/app/unibox/useThreadLabels";
 import useSetThreadLabels from "@/lib/api/hooks/app/unibox/useSetThreadLabels";
-import { tagMeaning } from "@/lib/unibox/tagMeanings";
+import { TagMeaningTooltip } from "@/components/ui/tag-meaning-tooltip";
 
 interface Props {
   threadId: string;
@@ -180,9 +180,9 @@ export function ThreadLabelMenu({ threadId, open, onOpenChange }: Props) {
                     className="size-2.5 rounded-full shrink-0"
                     style={{ backgroundColor: c.color }}
                   />
-                  <span className="truncate" title={tagMeaning(c.title) || undefined}>
-                    {c.title}
-                  </span>
+                  <TagMeaningTooltip title={c.title}>
+                    <span className="truncate">{c.title}</span>
+                  </TagMeaningTooltip>
                   {checked && (
                     <span className="ml-auto text-[10px] text-slate-300">assigned</span>
                   )}
diff --git a/web/src/components/ui/tag-meaning-tooltip.tsx b/web/src/components/ui/tag-meaning-tooltip.tsx
new file mode 100644
index 000000000..69da8b0da
--- /dev/null
+++ b/web/src/components/ui/tag-meaning-tooltip.tsx
@@ -0,0 +1,18 @@
+import type { ReactElement } from "react";
+
+import { tagMeaning } from "@/lib/unibox/tagMeanings";
+import { Tooltip, TooltipContent, TooltipTrigger } from "@/components/ui/tooltip";
+
+export function TagMeaningTooltip({ title, children }: { title: string; children: ReactElement }) {
+    const meaning = tagMeaning(title);
+    if (!meaning) return children;
+
+    return (
+        <Tooltip>
+            <TooltipTrigger asChild>{children}</TooltipTrigger>
+            <TooltipContent sideOffset={6} className="max-w-72">
+                {meaning}
+            </TooltipContent>
+        </Tooltip>
+    );
+}