diff --git a/apps/api/src/app/__tests__/first-party-substitution.test.ts b/apps/api/src/app/__tests__/first-party-substitution.test.ts
new file mode 100644
index 0000000..86bebe3
--- /dev/null
+++ b/apps/api/src/app/__tests__/first-party-substitution.test.ts
@@ -0,0 +1,129 @@
+/**
+ * ACT-WORK-05 差异评估的两枚纯工具 —— 「能算的不问 LLM」:同输入必同结论。
+ * 用例逐条对应《ACT-WORK-05-活动流程与工单说明》§八的示例矩阵:
+ * A XL2596S-5.0 条件推荐(使能阈值未披露 → UNKNOWN)/ B LM2596S-ADJ 备选(可调版靠外围配成 5V)/
+ * C 国产 DCDC 不推荐(输入上限 32V < 客户 40V,硬约束 MISMATCH)。
+ */
+import { describe, expect, it } from 'vitest';
+import { FIRST_PARTY_TOOLS } from '../tools/first-party.ts';
+
+const handler = (name: string) => {
+  const found = FIRST_PARTY_TOOLS.find(([n]) => n === name);
+  if (found === undefined) throw new Error(`没有工具 ${name}`);
+  return found[1];
+};
+/** ToolHandler 的入参形状见 `apps/api/src/modules/toolbox/internal/adapter/toolbox-store.ts`:纯工具不用连接目标 */
+const call = async (name: string, input: Record<string, unknown>) => {
+  const out = await handler(name)({ input, connection: {}, operation: undefined, idempotencyKey: undefined });
+  if (!out.ok) throw new Error(`工具失败:${JSON.stringify(out)}`);
+  return out.output as Record<string, unknown>;
+};
+
+type Item = { parameterName: string; compareResult: string; differenceStatus: string; riskLevel: string };
+type Result = { candidateInternalPn: string; items: Item[]; counts: Record<string, number> };
+
+const pair = (parameterName: string, originalValue: string, candidateValue: string, constraintType: 'hard' | 'soft', extra: Record<string, string> = {}) => ({
+  parameterName,
+  originalValue,
+  candidateValue,
+  constraintType,
+  evidenceRef: 'P-08 · P-10 Rev H',
+  ...extra,
+});
+
+describe('compare-parameters:逐参数四态', () => {
+  it('候选温域更宽 → covers → MATCH 低风险;固定 vs 可调 → configurable → CONDITIONAL;未披露 → UNKNOWN', async () => {
+    const out = await call('part-substitution-assessment.compare-parameters', {
+      candidates: [
+        {
+          candidateInternalPn: 'XL2596S-5.0',
+          pairs: [
+            pair('工作温度', '-40~+85', '-40~+125', 'hard', { unit: '℃' }),
+            pair('输出电压', '5.0', '5.0', 'hard', { unit: 'V' }),
+            pair('使能阈值', '1.4', '未披露', 'hard', { unit: 'V' }),
+            pair('静态电流', '5', '4.2', 'soft', { unit: 'mA' }),
+          ],
+        },
+        {
+          candidateInternalPn: 'LM2596S-ADJ',
+          pairs: [pair('输出电压', '5.0', '1.23~37', 'hard', { unit: 'V' })],
+        },
+      ],
+    });
+    const results = out['results'] as Result[];
+    const a = results[0]!;
+    const b = results[1]!;
+    expect(out['ruleVersion']).toBe('R-2026.07');
+    const by = (r: Result, name: string) => r.items.find((i) => i.parameterName === name);
+    expect(by(a, '工作温度')).toMatchObject({ compareResult: 'covers', differenceStatus: 'match', riskLevel: 'low' });
+    expect(by(a, '输出电压')).toMatchObject({ compareResult: 'equal', differenceStatus: 'match' });
+    expect(by(a, '使能阈值')).toMatchObject({ compareResult: 'unknown', differenceStatus: 'unknown', riskLevel: 'medium' });
+    expect(by(a, '静态电流')).toMatchObject({ differenceStatus: 'conditional' }); // 软约束数值不同 → 条件
+    expect(a.counts).toMatchObject({ match: 2, unknown: 1, conditional: 1, mismatch: 0, hardMismatch: 0 });
+    expect(by(b, '输出电压')).toMatchObject({ compareResult: 'configurable', differenceStatus: 'conditional' });
+    expect(b.counts['configurable']).toBe(1);
+  });
+
+  it('硬约束范围变窄 → MISMATCH 高风险;客户约束(requirement)不满足也是 MISMATCH', async () => {
+    const out = await call('part-substitution-assessment.compare-parameters', {
+      candidates: [
+        {
+          candidateInternalPn: 'CN-DCDC-32V',
+          pairs: [
+            pair('输入电压范围', '4.5~40', '4.5~32', 'hard', { unit: 'V', requirement: '>= 40' }),
+            pair('封装', 'TO-263-5', 'TO-263-5', 'hard'),
+          ],
+        },
+      ],
+    });
+    const c = (out['results'] as Result[])[0]!;
+    expect(c.items[0]).toMatchObject({ compareResult: 'narrower', differenceStatus: 'mismatch', riskLevel: 'high' });
+    expect(c.items[1]).toMatchObject({ compareResult: 'equal', differenceStatus: 'match' });
+    expect(c.counts).toMatchObject({ mismatch: 1, hardMismatch: 1, match: 1 });
+  });
+
+  it('硬约束相等但没有证据引用 → 不判 MATCH,降为 CONDITIONAL(硬约束项未经证据支持不得判 MATCH)', async () => {
+    const out = await call('part-substitution-assessment.compare-parameters', {
+      candidates: [{ candidateInternalPn: 'X', pairs: [{ parameterName: '封装', originalValue: 'TO-263-5', candidateValue: 'TO-263-5', constraintType: 'hard' }] }],
+    });
+    const x = (out['results'] as Result[])[0]!;
+    expect(x.items[0]).toMatchObject({ compareResult: 'equal', differenceStatus: 'conditional' });
+  });
+
+  it('数值带单位/括号注记也认得:「5.0(固定)」「3A」「150 kHz」;生命周期按活跃度比', async () => {
+    const out = await call('part-substitution-assessment.compare-parameters', {
+      candidates: [{ candidateInternalPn: 'X', pairs: [pair('输出电压', '5.0(固定)', '5.0 V', 'hard'), pair('输出电流', '3A', '3', 'hard'), pair('开关频率', '150 kHz', '150', 'hard'), pair('生命周期', 'nrnd', 'active', 'soft')] }],
+    });
+    const x = (out['results'] as Result[])[0]!;
+    // 生命周期不是数值:候选比原料更活(nrnd → active)算 covers → MATCH,替 NRND 料本就是为了这个
+    expect(x.items.map((i) => i.differenceStatus)).toEqual(['match', 'match', 'match', 'match']);
+    expect(x.items[3]?.compareResult).toBe('covers');
+  });
+});
+
+describe('recommend:推荐等级四档', () => {
+  it('硬约束 MISMATCH → 不推荐;有 UNKNOWN → 条件推荐;只有 configurable → 备选;全 MATCH → 推荐', async () => {
+    const out = await call('part-substitution-assessment.recommend', {
+      candidates: [
+        { candidateInternalPn: 'C', counts: { match: 5, mismatch: 1, unknown: 0, conditional: 0, hardMismatch: 1, softMismatch: 0, configurable: 0 } },
+        { candidateInternalPn: 'A', counts: { match: 5, mismatch: 0, unknown: 1, conditional: 0, hardMismatch: 0, softMismatch: 0, configurable: 0 } },
+        { candidateInternalPn: 'B', counts: { match: 6, mismatch: 0, unknown: 0, conditional: 1, hardMismatch: 0, softMismatch: 0, configurable: 1 } },
+        { candidateInternalPn: 'D', counts: { match: 7, mismatch: 0, unknown: 0, conditional: 0, hardMismatch: 0, softMismatch: 0, configurable: 0 } },
+      ],
+    });
+    const results = out['results'] as Array<{ candidateInternalPn: string; recommendationLevel: string; riskLevel: string }>;
+    expect(results.map((r) => [r.candidateInternalPn, r.recommendationLevel, r.riskLevel])).toEqual([
+      ['C', 'not_recommended', 'high'],
+      ['A', 'conditional', 'medium'],
+      ['B', 'alternate', 'medium'],
+      ['D', 'recommended', 'low'],
+    ]);
+  });
+
+  it('既有 UNKNOWN 又有 configurable:UNKNOWN 优先 → 条件推荐(验证闭环前不给备选)', async () => {
+    const out = await call('part-substitution-assessment.recommend', {
+      candidates: [{ candidateInternalPn: 'E', counts: { match: 1, mismatch: 0, unknown: 1, conditional: 1, hardMismatch: 0, softMismatch: 0, configurable: 1 } }],
+    });
+    expect((out['results'] as Array<{ recommendationLevel: string }>)[0]?.recommendationLevel).toBe('conditional');
+  });
+});
diff --git a/apps/api/src/app/seed-mvp.ts b/apps/api/src/app/seed-mvp.ts
index cad8758..fc6d5d4 100644
--- a/apps/api/src/app/seed-mvp.ts
+++ b/apps/api/src/app/seed-mvp.ts
@@ -12,6 +12,7 @@ import type { Container } from './container.ts';
 import { installRealActivities } from './seed-activities.ts';
 import { installSlots } from './seed-mvp-slots.ts';
 import { seedMvpFlow } from './seed-mvp-flow.ts';
+import { W05_TOOLS } from './tools-w05.ts';
 
 /** 第一方功能工具:查历史价 —— MVP 用录制回放替身代真 CRM(README:mock 只在外界) */
 const HISTORY_TOOL = {
@@ -328,7 +329,7 @@ export async function seedMvp(container: Container): Promise<void> {
   log(`① LLM 实例已绑定:deepseek-v4-flash · deepseek-v4-pro${apiKey === undefined ? '(环境无密钥 —— 两条都是未绑定,去治理台补)' : ''}`);
 
   /* ② 功能工具注册两审 + 逐槽位白名单 */
-  for (const contract of [HISTORY_TOOL, MAIL_TOOL, CLASSIFY_TOOL, PLACEHOLDER_TOOL, COVERAGE_SCORE_TOOL, RANK_KEY_PERSONS_TOOL]) {
+  for (const contract of [HISTORY_TOOL, MAIL_TOOL, CLASSIFY_TOOL, PLACEHOLDER_TOOL, COVERAGE_SCORE_TOOL, RANK_KEY_PERSONS_TOOL, ...W05_TOOLS]) {
     const verdict = await container.toolbox.register({
       contract,
       samples: [
@@ -359,7 +360,7 @@ export async function seedMvp(container: Container): Promise<void> {
   for (const [activityId, tools] of Object.entries(ALLOWLIST)) {
     await container.toolbox.setAllowlist(activityId, tools);
   }
-  log('② 功能工具已注册并入白名单(读类 1 · 写类 1 · 纯工具 4,逐活动授权)');
+  log('② 功能工具已注册并入白名单(读类 1 · 写类 1 · 纯工具 6,逐活动授权)');
 
   /*
    * ③ 活动装入 —— 两批:
diff --git a/apps/api/src/app/tools-w05.ts b/apps/api/src/app/tools-w05.ts
new file mode 100644
index 0000000..219e0c7
--- /dev/null
+++ b/apps/api/src/app/tools-w05.ts
@@ -0,0 +1,87 @@
+/**
+ * ACT-WORK-05 差异评估的两枚纯工具契约(活动私有作用域)。
+ * 两处消费:`seed-mvp.ts`(db:seed 全套播种)与 `seed-activities.ts`(activities:install 装活动时顺带注册 ——
+ * 「安装即用」包含它声明过的纯工具能调得动;从前 E04 的工具只在 db:seed 里注册,开发机上只跑
+ * activities:install 的人第一次跑活动就撞「工具不存在」)。
+ */
+const PURE = {
+  effect: 'read' as const,
+  errors: [] as Array<{ code: string; retryable: boolean; message: string }>,
+  idempotent: true,
+  timeoutMs: 5_000,
+  retries: 0,
+  connectionKeys: [] as string[],
+  pure: true,
+  ownerActivityId: 'part-substitution-assessment',
+};
+
+/** 逐参数比对 —— 出参键与台账列同名(difference_status / risk_level),模型照抄 */
+export const COMPARE_PARAMETERS_TOOL = {
+  ...PURE,
+  name: 'part-substitution-assessment.compare-parameters',
+  displayName: '替代料逐参数比对',
+  version: '1.0.0',
+  description:
+    '按硬/软约束逐参数比对原 PN 与候选 PN,输出四态 difference_status(match/mismatch/unknown/conditional)、' +
+    'compare_result、risk_level 与各候选的计数。一次可比一批候选(candidates 数组),每对参数可带客户约束 requirement(如 ">= 40")与证据引用 evidenceRef;' +
+    '硬约束没有证据引用不判 match。规则版本 R-2026.07。',
+  input: {
+    type: 'object',
+    properties: {
+      candidates: {
+        type: 'array',
+        description: '[{candidateInternalPn, pairs:[{parameterName, originalValue, candidateValue, unit?, constraintType:"hard"|"soft", requirement?, evidenceRef?}]}]',
+      },
+    },
+  },
+  output: {
+    type: 'object',
+    properties: {
+      ruleVersion: { type: 'string' },
+      results: {
+        type: 'array',
+        description: '[{candidateInternalPn, items:[{parameterName, unit, constraintType, compareResult, differenceStatus, riskLevel, note}], counts:{match,mismatch,unknown,conditional,hardMismatch,softMismatch,configurable}}]',
+      },
+    },
+  },
+};
+
+/** 推荐定级 —— 出参 recommendationLevel / riskLevel / reason 直接落 P-11 */
+export const RECOMMEND_TOOL = {
+  ...PURE,
+  name: 'part-substitution-assessment.recommend',
+  displayName: '替代推荐定级',
+  version: '1.0.0',
+  description:
+    '按每个候选的比对计数定推荐等级:硬约束 mismatch>0 → not_recommended;unknown>0 → conditional;' +
+    '只有可调配成(configurable)→ alternate;其余 conditional → conditional;全 match → recommended。',
+  input: {
+    type: 'object',
+    properties: {
+      candidates: { type: 'array', description: '[{candidateInternalPn, counts:{match,mismatch,unknown,conditional,hardMismatch,softMismatch,configurable}}]' },
+    },
+  },
+  output: {
+    type: 'object',
+    properties: {
+      ruleVersion: { type: 'string' },
+      results: { type: 'array', description: '[{candidateInternalPn, recommendationLevel, riskLevel, reason}]' },
+    },
+  },
+};
+
+export const W05_TOOLS = [COMPARE_PARAMETERS_TOOL, RECOMMEND_TOOL] as const;
+
+/** 试运行审的样例(两件共用一份:并集覆盖各家入参) */
+export const W05_TOOL_SAMPLE = {
+  input: {
+    candidates: [
+      {
+        candidateInternalPn: 'XL2596S-5.0',
+        pairs: [{ parameterName: '输出电压', originalValue: '5.0', candidateValue: '5.0', unit: 'V', constraintType: 'hard', evidenceRef: 'P-08' }],
+        counts: { match: 1, mismatch: 0, unknown: 0, conditional: 0, hardMismatch: 0, softMismatch: 0, configurable: 0 },
+      },
+    ],
+  },
+  expectShape: { type: 'object' },
+};
diff --git a/apps/api/src/app/tools/first-party.ts b/apps/api/src/app/tools/first-party.ts
index 367da49..691efbf 100644
--- a/apps/api/src/app/tools/first-party.ts
+++ b/apps/api/src/app/tools/first-party.ts
@@ -332,6 +332,154 @@ const slotPlaceholder: ToolHandler = async ({ input }) => {
   };
 };
 
+/* ── ACT-WORK-05 差异评估:逐参数比对 —— 纯工具(活动私有作用域)─────────────────
+ *
+ * 「能算的不问 LLM」:同输入必同结论。规则与活动包 manifest 里的 D01/D02 两张 DMN 同一份;
+ * 这里是求值器,那里是随包冻结的文档。`RULE_VERSION` 随结论落账(rule_version)。
+ *
+ * 比对语义(按硬/软约束):
+ *   equal / covers(候选范围 ⊇ 原范围) → match,低风险;
+ *   configurable(原是定值、候选是含它的可调范围)→ conditional(要改外围);
+ *   narrower / differs / partial → 硬:mismatch 高风险;软:conditional 中风险;
+ *   任一侧未披露 → unknown 中风险;
+ *   硬约束 equal/covers 但没给 evidenceRef → conditional(硬约束未经证据支持不得判 MATCH);
+ *   requirement(客户约束,如 ">= 40")候选不满足 → 一律 mismatch 高风险。
+ */
+export const SUBSTITUTION_RULE_VERSION = 'R-2026.07';
+
+type Parsed = { kind: 'number'; value: number } | { kind: 'range'; lo: number; hi: number } | { kind: 'text'; value: string } | { kind: 'unknown' };
+type CompareResult = 'equal' | 'covers' | 'configurable' | 'narrower' | 'partial' | 'differs' | 'unknown';
+type DifferenceStatus = 'match' | 'mismatch' | 'unknown' | 'conditional';
+type RiskLevel = 'low' | 'medium' | 'high';
+type ParamPair = {
+  parameterName: string;
+  originalValue: string;
+  candidateValue: string;
+  unit?: string;
+  constraintType: 'hard' | 'soft';
+  requirement?: string;
+  evidenceRef?: string;
+};
+type CompareCounts = { match: number; mismatch: number; unknown: number; conditional: number; hardMismatch: number; softMismatch: number; configurable: number };
+
+const UNKNOWN_WORDS = /^(未披露|未知|未给出|unknown|n\/?a|tbd|待定|-|—|–)$/i;
+const NUM = '[-+]?\\d+(?:\\.\\d+)?';
+const RANGE_RE = new RegExp(`^(${NUM})\\s*(?:~|～|-|–|—|至|to)\\s*(${NUM})`, 'i');
+const NUM_RE = new RegExp(`^(${NUM})`);
+
+export function parseParamValue(raw: unknown): Parsed {
+  const s = String(raw ?? '').trim().replace(/\s+/g, ' ');
+  if (s === '' || UNKNOWN_WORDS.test(s)) return { kind: 'unknown' };
+  const r = RANGE_RE.exec(s);
+  if (r !== null) {
+    const lo = Number(r[1]);
+    const hi = Number(r[2]);
+    if (Number.isFinite(lo) && Number.isFinite(hi)) return { kind: 'range', lo: Math.min(lo, hi), hi: Math.max(lo, hi) };
+  }
+  const n = NUM_RE.exec(s);
+  if (n !== null && Number.isFinite(Number(n[1]))) return { kind: 'number', value: Number(n[1]) };
+  return { kind: 'text', value: s.toLowerCase() };
+}
+
+function compareParsed(o: Parsed, c: Parsed): CompareResult {
+  if (o.kind === 'unknown' || c.kind === 'unknown') return 'unknown';
+  if (o.kind === 'range' && c.kind === 'range') {
+    if (c.lo === o.lo && c.hi === o.hi) return 'equal';
+    if (c.lo <= o.lo && c.hi >= o.hi) return 'covers';
+    if (c.lo >= o.lo && c.hi <= o.hi) return 'narrower';
+    return c.hi < o.lo || c.lo > o.hi ? 'differs' : 'partial';
+  }
+  if (o.kind === 'number' && c.kind === 'number') return Math.abs(o.value - c.value) <= 1e-9 ? 'equal' : 'differs';
+  if (o.kind === 'number' && c.kind === 'range') return c.lo <= o.value && o.value <= c.hi ? 'configurable' : 'differs';
+  if (o.kind === 'range' && c.kind === 'number') return o.lo <= c.value && c.value <= o.hi ? 'narrower' : 'differs';
+  if (o.kind === 'text' && c.kind === 'text') return o.value === c.value ? 'equal' : 'differs';
+  return 'differs';
+}
+
+/** 客户约束:">= 40" / "<= 85" / "-40~85"(候选必须盖住);解析不了当没给 */
+function satisfiesRequirement(requirement: string | undefined, c: Parsed): boolean | undefined {
+  if (requirement === undefined || requirement.trim() === '' || c.kind === 'unknown' || c.kind === 'text') return undefined;
+  const s = requirement.trim();
+  const ge = new RegExp(`^(?:>=|≥)\\s*(${NUM})$`).exec(s);
+  const le = new RegExp(`^(?:<=|≤)\\s*(${NUM})$`).exec(s);
+  const hi = c.kind === 'range' ? c.hi : c.value;
+  const lo = c.kind === 'range' ? c.lo : c.value;
+  if (ge !== null) return hi >= Number(ge[1]);
+  if (le !== null) return lo <= Number(le[1]);
+  const req = parseParamValue(s);
+  if (req.kind === 'range') return lo <= req.lo && hi >= req.hi;
+  if (req.kind === 'number') return lo <= req.value && hi >= req.value;
+  return undefined;
+}
+
+/** 生命周期不是数值:候选比原料「更活」算 covers(替 NRND 料本就是为了这个),更差才是 differs */
+const LIFECYCLE_ORDER: Record<string, number> = { active: 3, nrnd: 2, risk: 2, eol: 1, discontinued: 0 };
+function compareLifecycle(o: string, c: string): CompareResult | undefined {
+  const ro = LIFECYCLE_ORDER[o.trim().toLowerCase()];
+  const rc = LIFECYCLE_ORDER[c.trim().toLowerCase()];
+  if (ro === undefined || rc === undefined) return undefined;
+  return rc === ro ? 'equal' : rc > ro ? 'covers' : 'differs';
+}
+
+function judgePair(p: ParamPair): { compareResult: CompareResult; differenceStatus: DifferenceStatus; riskLevel: RiskLevel; note: string } {
+  const o = parseParamValue(p.originalValue);
+  const c = parseParamValue(p.candidateValue);
+  const hard = p.constraintType === 'hard';
+  let compareResult = compareParsed(o, c);
+  if (/生命周期|lifecycle/i.test(p.parameterName)) compareResult = compareLifecycle(p.originalValue, p.candidateValue) ?? compareResult;
+  const req = satisfiesRequirement(p.requirement, c);
+  if (req === false) {
+    // 客户约束不满足:比对结果照实留(narrower/differs),结论一律 MISMATCH 高风险
+    return { compareResult: compareResult === 'unknown' ? 'differs' : compareResult, differenceStatus: 'mismatch', riskLevel: 'high', note: `不满足客户约束 ${p.requirement ?? ''}` };
+  }
+  if (compareResult === 'unknown') return { compareResult, differenceStatus: 'unknown', riskLevel: 'medium', note: '一侧未披露:标 UNKNOWN,挂验证任务或补来源' };
+  if (compareResult === 'equal' || compareResult === 'covers') {
+    if (hard && (p.evidenceRef === undefined || p.evidenceRef.trim() === '')) {
+      return { compareResult, differenceStatus: 'conditional', riskLevel: 'medium', note: '硬约束缺证据引用:未经证据支持不判 MATCH' };
+    }
+    return { compareResult, differenceStatus: 'match', riskLevel: 'low', note: compareResult === 'covers' ? '候选范围盖住原范围' : '一致' };
+  }
+  if (compareResult === 'configurable') return { compareResult, differenceStatus: 'conditional', riskLevel: 'medium', note: '候选可调,须改外围把它配成原值' };
+  if (compareResult === 'partial') return { compareResult, differenceStatus: 'conditional', riskLevel: hard ? 'medium' : 'low', note: '范围部分重叠,须按应用边界确认' };
+  compareResult = compareResult === 'narrower' ? 'narrower' : 'differs';
+  return hard
+    ? { compareResult, differenceStatus: 'mismatch', riskLevel: 'high', note: '硬约束不一致' }
+    : { compareResult, differenceStatus: 'conditional', riskLevel: 'medium', note: '软约束不一致,须评估影响' };
+}
+
+const compareParameters: ToolHandler = async ({ input }) => {
+  const candidates = Array.isArray(input['candidates']) ? (input['candidates'] as Array<{ candidateInternalPn: string; pairs: ParamPair[] }>) : [];
+  const results = candidates.map((cand) => {
+    const counts: CompareCounts = { match: 0, mismatch: 0, unknown: 0, conditional: 0, hardMismatch: 0, softMismatch: 0, configurable: 0 };
+    const items = (Array.isArray(cand.pairs) ? cand.pairs : []).map((p) => {
+      const j = judgePair(p);
+      counts[j.differenceStatus] += 1;
+      if (j.differenceStatus === 'mismatch') counts[p.constraintType === 'hard' ? 'hardMismatch' : 'softMismatch'] += 1;
+      if (j.compareResult === 'configurable') counts.configurable += 1;
+      return { parameterName: p.parameterName, unit: p.unit ?? '', constraintType: p.constraintType, ...j };
+    });
+    return { candidateInternalPn: cand.candidateInternalPn, items, counts };
+  });
+  return { ok: true, output: { ruleVersion: SUBSTITUTION_RULE_VERSION, results } };
+};
+
+/**
+ * 推荐定级(D02,FIRST):硬 MISMATCH → 不推荐;有 UNKNOWN → 条件推荐(等验证闭环);
+ * 有 configurable(改外围配得成)→ 备选;其余 conditional → 条件推荐;全 MATCH → 推荐。与 manifest 里的 D02 表同一份规则。
+ */
+const recommend: ToolHandler = async ({ input }) => {
+  const candidates = Array.isArray(input['candidates']) ? (input['candidates'] as Array<{ candidateInternalPn: string; counts: Partial<CompareCounts> }>) : [];
+  const results = candidates.map((cand) => {
+    const n = (k: keyof CompareCounts) => Number(cand.counts?.[k] ?? 0);
+    if (n('hardMismatch') > 0) return { candidateInternalPn: cand.candidateInternalPn, recommendationLevel: 'not_recommended', riskLevel: 'high', reason: `硬约束 MISMATCH ${n('hardMismatch')} 项:硬约束失败直接不推荐` };
+    if (n('unknown') > 0) return { candidateInternalPn: cand.candidateInternalPn, recommendationLevel: 'conditional', riskLevel: 'medium', reason: `UNKNOWN ${n('unknown')} 项待验证闭环,通过后可升级推荐` };
+    if (n('configurable') > 0) return { candidateInternalPn: cand.candidateInternalPn, recommendationLevel: 'alternate', riskLevel: 'medium', reason: `${n('configurable')} 项须改外围配成原值(另有 ${n('conditional') - n('configurable')} 项条件差异):客户接受改设计则启用` };
+    if (n('conditional') > 0) return { candidateInternalPn: cand.candidateInternalPn, recommendationLevel: 'conditional', riskLevel: 'medium', reason: `CONDITIONAL ${n('conditional')} 项须按应用边界确认` };
+    return { candidateInternalPn: cand.candidateInternalPn, recommendationLevel: 'recommended', riskLevel: 'low', reason: `${n('match')} 项全部 MATCH` };
+  });
+  return { ok: true, output: { ruleVersion: SUBSTITUTION_RULE_VERSION, results } };
+};
+
 export const FIRST_PARTY_TOOLS: ReadonlyArray<readonly [string, ToolHandler]> = [
   ['crm.history-price-read', historyPriceRead],
   ['quote-intake.classify', classify],
@@ -343,4 +491,6 @@ export const FIRST_PARTY_TOOLS: ReadonlyArray<readonly [string, ToolHandler]> =
   ['slot.placeholder', slotPlaceholder],
   ['crm-relationship-coverage.recompute-score', recomputeScore],
   ['crm-relationship-coverage.rank-key-persons', rankKeyPersons],
+  ['part-substitution-assessment.compare-parameters', compareParameters],
+  ['part-substitution-assessment.recommend', recommend],
 ];