diff --git a/apps/web/src/routes/categories/[categoryId]/prompt/+page.svelte b/apps/web/src/routes/categories/[categoryId]/prompt/+page.svelte
index b01452c..ae0555b 100644
--- a/apps/web/src/routes/categories/[categoryId]/prompt/+page.svelte
+++ b/apps/web/src/routes/categories/[categoryId]/prompt/+page.svelte
@@ -20,7 +20,6 @@
 	import Spinner from "$lib/components/Spinner.svelte";
 	import ContentLanguageSwitcher from "$lib/components/ContentLanguageSwitcher.svelte";
 	import {
-		Badge,
 		Button,
 		Card,
 		CardContent,
@@ -103,7 +102,6 @@
 	let assignOpen = $state(false);
 
 	let activeSection = $state<EnhancePromptSectionId>("title");
-	let preamble = $state(DEFAULT_ENHANCE_PREAMBLE);
 	let sectionBodies = $state<Record<EnhancePromptSectionId, string>>({
 		title: "",
 		description: "",
@@ -138,14 +136,14 @@
 
 	function syncEditorFromStored(raw: string) {
 		const parsed = parseEnhancePrompt(raw);
-		preamble = parsed.preamble || DEFAULT_ENHANCE_PREAMBLE;
 		sectionBodies = { ...parsed.sections };
 		unstructuredHint = Boolean(raw.trim()) && !parsed.hasRoleSections;
 	}
 
 	function currentCombined(): string {
-		if (isEnhancePromptEmpty(preamble, sectionBodies)) return "";
-		return composeEnhancePrompt(preamble, sectionBodies);
+		// Shared JSON schema intro is system-owned (not editable in the UI).
+		if (isEnhancePromptEmpty(DEFAULT_ENHANCE_PREAMBLE, sectionBodies)) return "";
+		return composeEnhancePrompt(DEFAULT_ENHANCE_PREAMBLE, sectionBodies);
 	}
 
 	function flushEditorToLang() {
@@ -247,7 +245,6 @@
 	}
 
 	function clearLanguageOverride() {
-		preamble = DEFAULT_ENHANCE_PREAMBLE;
 		sectionBodies = { title: "", description: "", meta: "", attributes: "" };
 		unstructuredHint = false;
 		const next = { ...promptsByLang };
@@ -460,21 +457,7 @@
 							<CardDescription>{i18n.t(sectionMeta.helpKey)}</CardDescription>
 						</CardHeader>
 						<CardContent class="space-y-4">
-							<div class="rounded-md border bg-muted/30 p-3 space-y-2">
-								<div class="flex flex-wrap items-center gap-2">
-									<span class="text-xs font-semibold uppercase tracking-wide text-muted-foreground">
-										{i18n.t("categories.promptSection.schemaHeading")}
-									</span>
-									{#each schemaHint.jsonKeys as key}
-										<Badge variant="secondary" class="font-mono text-xs">{key}</Badge>
-									{/each}
-								</div>
-								<p class="text-xs text-muted-foreground">
-									{i18n.t("categories.promptSection.schemaHelp")}
-								</p>
-								<pre class="overflow-x-auto rounded bg-background/80 px-2 py-1.5 font-mono text-xs text-foreground/90">{schemaHint.example}</pre>
-								<p class="text-xs text-muted-foreground">{i18n.t(sectionMeta.formulaNoteKey)}</p>
-							</div>
+							<p class="text-xs text-muted-foreground">{i18n.t(sectionMeta.formulaNoteKey)}</p>
 
 							<div class="flex flex-wrap gap-2">
 								{#each sectionVars as v}
@@ -521,25 +504,6 @@
 									{/if}
 								</p>
 							</div>
-
-							<details class="rounded-md border p-3">
-								<summary class="cursor-pointer text-sm font-medium">
-									{i18n.t("categories.promptSection.preambleToggle")}
-								</summary>
-								<div class="mt-3 space-y-2">
-									<p class="text-xs text-muted-foreground">
-										{i18n.t("categories.promptSection.preambleHelp")}
-									</p>
-									<Textarea
-										id="category-prompt-preamble"
-										value={preamble}
-										oninput={(e) =>
-											(preamble = (e.currentTarget as HTMLTextAreaElement).value)}
-										rows={4}
-										class="font-mono text-sm"
-									/>
-								</div>
-							</details>
 						</CardContent>
 					</Card>
 				</div>