diff --git a/src/app/actions/create-run.ts b/src/app/actions/create-run.ts
index 7d08d63..7c5ecde 100644
--- a/src/app/actions/create-run.ts
+++ b/src/app/actions/create-run.ts
@@ -16,6 +16,8 @@ export async function createMockRunAction(
   _prevState: CreateRunFormState,
   formData: FormData,
 ): Promise<CreateRunFormState> {
+  // DB列名互換のためフォーム名はquestionを維持。
+  // UI上はResearch Topicとして扱い、既存API/永続化互換を壊さない。
   const raw = formData.get("question");
   if (typeof raw !== "string" || !raw.trim()) {
     return { error: "Research topic is required." };
@@ -31,6 +33,8 @@ export async function createMockRunAction(
     return { error: manualSourceUrlsResult.message };
   }
 
+  // runはowner scopeで分離する。未認証で作成させないことで
+  // 履歴閲覧/共有リンク管理の境界を単純に保つ。
   const currentUser = await getCurrentUser();
   if (!currentUser) {
     return { error: "Sign in is required to start an investigation." };
diff --git a/src/app/share/[token]/page.tsx b/src/app/share/[token]/page.tsx
index b75b51b..cd7478c 100644
--- a/src/app/share/[token]/page.tsx
+++ b/src/app/share/[token]/page.tsx
@@ -12,6 +12,8 @@ type SharePageProps = {
   params: Promise<{ token: string }>;
 };
 
+// 共有ページはトークン知識ベースの限定公開。
+// 検索エンジン経由の露出を避けるため noindex/nofollow を強制する。
 export const metadata = {
   robots: {
     index: false,
@@ -87,6 +89,7 @@ export default async function SharePage({ params }: SharePageProps) {
   const run = shareLink.analysisRun;
   const { answer, sources } = selectLatestAnswerSnapshotForView(run.answerSnapshots);
 
+  // 共有閲覧者には再実行権限がないため、失敗時は安全文言のみを表示する。
   if (run.status === "failed") {
     return (
       <main>
diff --git a/src/features/run/components/run-result-view.tsx b/src/features/run/components/run-result-view.tsx
index d5da320..cc75040 100644
--- a/src/features/run/components/run-result-view.tsx
+++ b/src/features/run/components/run-result-view.tsx
@@ -186,6 +186,8 @@ function edgeEndpoints(
   };
 }
 
+// TraceMapはチャット時系列ではなく調査導線を重視するため、
+// Mission -> Evidence -> Unknown -> Lineage -> Report の順を固定表示する。
 const INVESTIGATION_GUIDE_STEPS = [
   "Mission",
   "Evidence Map",
@@ -210,6 +212,8 @@ export function RunResultView({
   answerModel,
   answerGeneratedAt,
 }: RunResultViewProps) {
+  // グラフ/クレーム/ソース詳細を連動させる選択状態。
+  // どれかを起点にしても同じ調査対象へフォーカスできるようにする。
   const [selectedSourceId, setSelectedSourceId] = useState<string | null>(null);
   const [selectedGraphNodeId, setSelectedGraphNodeId] = useState<string | null>(
     null,
diff --git a/src/features/run/lib/build-source-lineage.ts b/src/features/run/lib/build-source-lineage.ts
index 039db7e..84d421b 100644
--- a/src/features/run/lib/build-source-lineage.ts
+++ b/src/features/run/lib/build-source-lineage.ts
@@ -83,6 +83,8 @@ function normalizeVerificationStatus(value: string | null | undefined): string |
   return value === "verified" ? "verified" : value ?? null;
 }
 
+// Source Lineage Lite は厳密な出典系譜DBではなく、
+// sourceType / primary判定 / publishedAt など既存スナップショットから推定する軽量ビュー。
 export function buildSourceLineage(params: {
   sources: SourceForLineage[];
   evidenceClaims: RunEvidenceClaim[];
diff --git a/src/features/run/lib/build-unknowns.ts b/src/features/run/lib/build-unknowns.ts
index 18f0142..c5b7ed1 100644
--- a/src/features/run/lib/build-unknowns.ts
+++ b/src/features/run/lib/build-unknowns.ts
@@ -15,6 +15,8 @@ function fromAlert(params: { id: string; message: string; level: AlertLevel; cla
   return { id: params.id, relatedClaimIds: params.claimSummary ? [params.id.split("-")[0]] : [], relatedSourceIds: [], text: params.claimSummary ? `${params.claimSummary}: ${params.message}` : params.message, reason: m.includes("primary source") ? "Primary or official evidence is missing." : "Existing evidence raised an investigation caveat.", severity: severityFromAlertLevel(params.level), category, suggestedNextAction: next, signals: ["alert"] };
 }
 
+// Unknown Mapは専用テーブルではなく、
+// claim/alert/source-qualityから派生する調査上の「未解決点ビュー」。
 export function buildUnknowns(params: { evidenceAlerts: RunEvidenceAlert[]; evidenceClaims: RunEvidenceClaim[]; sourceQuality?: SourceQualitySignal[]; sourceDrilldown?: SourceDetailDrilldown[] }): InvestigationUnknown[] {
   const unknowns: InvestigationUnknown[] = [];
   params.evidenceAlerts.forEach((a) => unknowns.push(fromAlert(a)));
@@ -40,6 +42,8 @@ export function buildUnknowns(params: { evidenceAlerts: RunEvidenceAlert[]; evid
     });
   });
 
+  // 同一論点の重複表示を避けるため、category+関連ID+reasonで集約し、
+  // severityが高いものを優先して残す。
   const deduped = new Map<string, InvestigationUnknown>();
   for (const u of unknowns) {
     const key = `${u.category}|${(u.relatedClaimIds ?? []).sort().join(",")}|${(u.relatedSourceIds ?? []).sort().join(",")}|${u.reason.toLowerCase()}`;
diff --git a/src/server/analysis/create-analysis-run-from-provider.ts b/src/server/analysis/create-analysis-run-from-provider.ts
index 9d83c04..dcbab1b 100644
--- a/src/server/analysis/create-analysis-run-from-provider.ts
+++ b/src/server/analysis/create-analysis-run-from-provider.ts
@@ -36,6 +36,8 @@ export async function createAnalysisRunFromProvider(
     options.mode ?? process.env.TRACEMAP_INVESTIGATION_MODE?.trim(),
   );
 
+  // 手動URL指定時はユーザーが明示した調査条件を優先し、
+  // 既存run cacheの再利用で入力意図が薄まることを避ける。
   const hasManualSourceUrls = (options.manualSourceUrls?.length ?? 0) > 0;
 
   const run = await prisma.analysisRun.create({
@@ -46,6 +48,8 @@ export async function createAnalysisRunFromProvider(
     },
   });
 
+  // MVP v2 は同期実行のため、run status は queued -> processing -> completed/failed を
+  // この関数内で完結させる。
   await prisma.analysisRun.update({
     where: { id: run.id },
     data: { status: "processing" },
@@ -61,6 +65,8 @@ export async function createAnalysisRunFromProvider(
   let payload: GeneratedAnswerGraphPayload | null = null;
   let shouldStoreRunCache = false;
 
+  // run cacheは「同一topic + provider + mode」でのみ再利用する。
+  // 手動URL付きrunは上書き条件なのでlookup自体を行わない。
   if (!hasManualSourceUrls) {
     try {
       const cached = await lookupRunCacheEntry(cacheKeyInfo);
@@ -100,6 +106,7 @@ export async function createAnalysisRunFromProvider(
       result = await provider.generateAnswerGraph({ question, sourceCandidates: sourceIntake.candidates, mode });
     } catch (cause) {
       console.error("[analysis] generateAnswerGraph threw", { runId: run.id, cause });
+      // provider例外は生メッセージをUIへ出さず、安全な固定文言へ変換して保存する。
       await prisma.analysisRun.update({
         where: { id: run.id },
         data: {
diff --git a/src/server/analysis/persist-generated-answer-graph.ts b/src/server/analysis/persist-generated-answer-graph.ts
index dde59ee..1d57272 100644
--- a/src/server/analysis/persist-generated-answer-graph.ts
+++ b/src/server/analysis/persist-generated-answer-graph.ts
@@ -105,6 +105,8 @@ export async function persistGeneratedAnswerGraph(params: {
 }): Promise<void> {
   const { runId, payload } = params;
 
+  // source検証はbest-effort。到達不能でもrun全体は継続し、
+  // Unknown/Source Quality側で「注意情報」として表示できる形に寄せる。
   const verificationByIndex = await Promise.all(
     payload.sources.map((src) =>
       shouldResolveSourceCache(src.url)
@@ -150,6 +152,8 @@ export async function persistGeneratedAnswerGraph(params: {
       idMap.set(placeholderId, row.id);
     }
 
+    // providerは仮ID(__src_n__)を返すため、永続化後のsourceSnapshotIdへ張り替えて
+    // graph snapshotをDB参照可能な形に正規化する。
     const graph = replaceGraphSourceIds(payload.answer.graphJson, idMap);
 
     await tx.answerSnapshot.update({
@@ -170,6 +174,7 @@ export async function persistGeneratedAnswerGraph(params: {
           },
         });
 
+        // claim-source参照はsupports優先。legacy配列は後方互換としてdirect supportへ変換。
         const supportRelations = c.supports
           ? c.supports.flatMap((support) => {
               const sourceSnapshotId = idMap.get(support.sourcePlaceholderId);
diff --git a/src/server/analysis/source-intake/source-intake-service.ts b/src/server/analysis/source-intake/source-intake-service.ts
index 6fcc125..590c572 100644
--- a/src/server/analysis/source-intake/source-intake-service.ts
+++ b/src/server/analysis/source-intake/source-intake-service.ts
@@ -20,6 +20,7 @@ export async function buildSourceIntakeFromQuestion(
   const discoveryProvider = resolveSourceDiscoveryProvider();
   const ignoredUrls: SourceIntakeResult["ignoredUrls"] = [];
 
+  // source discoveryは補助入力。失敗時もrunを止めず、ignoredUrlsへ理由を残す。
   let discoveredUrls: string[] = [];
   if (discoveryProvider.id !== "disabled") {
     const discovery = await discoveryProvider.discoverSources({
@@ -33,6 +34,8 @@ export async function buildSourceIntakeFromQuestion(
     }
   }
 
+  // manual > topic中URL > discovery候補を同一パイプラインへ流し、
+  // URL正規化/安全判定/重複排除を一箇所で適用する。
   const merged = [
     ...manualUrls.map((url) => ({ url, origin: "manual_url" as const })),
     ...topicUrls.map((url) => ({ url, origin: "topic_url" as const })),
@@ -57,6 +60,7 @@ export async function buildSourceIntakeFromQuestion(
       ignoredUrls.push({ url: item.url, reason: result.errorMessage });
       continue;
     }
+    // 最終URLではなくnormalized URLでdedupeし、同一記事の追跡パラメータ差分を吸収する。
     if (seen.has(result.normalizedUrl)) continue;
     seen.add(result.normalizedUrl);
 
diff --git a/src/types/answer-graph-generation.ts b/src/types/answer-graph-generation.ts
index 0735329..cc8253a 100644
--- a/src/types/answer-graph-generation.ts
+++ b/src/types/answer-graph-generation.ts
@@ -101,6 +101,10 @@ export type GeneratedEvidenceBundle = {
 };
 
 /** Persistable result of a successful generation step (DB writer consumes this). */
+/**
+ * provider出力を永続化用へ正規化した中間payload。
+ * graphJsonは描画スナップショットで、claim/source実体は別テーブルへ保存される。
+ */
 export type GeneratedAnswerGraphPayload = {
   answer: {
     title: string | null;
diff --git a/tests/source-intake.test.ts b/tests/source-intake.test.ts
index 520ee5d..0928cdd 100644
--- a/tests/source-intake.test.ts
+++ b/tests/source-intake.test.ts
@@ -4,6 +4,7 @@ import { extractUrls } from "@/server/analysis/source-intake/extract-urls";
 import { normalizeSourceUrl } from "@/server/analysis/source-url-normalization";
 import { isSourceFetchSafe } from "@/server/analysis/source-fetch-safety";
 
+// Source intakeは「抽出→正規化→安全判定」の入口仕様を守るテスト。
 describe("source intake basics", () => {
   it("extracts multiple http/https URLs and trims trailing punctuation", () => {
     const result = extractUrls("See https://Example.com/a, and http://example.org/b?x=1.");