fix(mcp): restore home-tenant access for delegated (MSP) admins

A delegated admin who is also a member/operator of their own home tenant
lost MCP access to it: any non-empty delegated scope flipped the whole
session to delegated cross-tenant routing, and enforceDelegatedTenant
rejected every tenant outside the managed set — which never contains the
home tenant (GetScopeAsync uses the home tid only as the Enterprise
entitlement gate, never adds it to the scope).

Fix is MCP-only (no backend change; the backend already authorizes the
home tenant via MemberRead and bounds the /api/global/* drill away from
it, so the home tenant must route to the JWT-bound member path):

- access-guard.ts: thread homeTenantId (JWT tid, lowercased) into the
  caller context.
- client.ts: getHomeTenantId(); enforceDelegatedTenant accepts
  managed union {home}; enforceDelegatedTenantForPage resolves a
  non-global tenant-path nextLink (no embedded tenantId) to home so
  page-2 re-selects the member path; pickGlobalOrTenantPath gains an
  effectiveTenantId arg and routes delegated+home to the tenant path.
- 16 pattern-A tool call sites pass the effective tenantId (not
  devices/blocked, which is platform-only).
- shared.ts / index.ts: descriptions + instructions surface the home
  tenant as an addressable target.

The home tenant is accepted optimistically at the MCP boundary; the
backend MemberRead stays authoritative (a non-member is denied on the
member path, so no leak). Continuation defense-in-depth preserved.

Verify: tsc clean; vitest 352 passed (+7 home-tenant cases).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/McpServer/autopilot-monitor-mcp/src/__tests__/client-routing.test.ts

@@ -18,6 +18,7 @@ import {
   hasCrossTenantRouting,
   isDelegated,
   getDelegatedTenantIds,
+  getHomeTenantId,
   enforceDelegatedTenant,
   enforceDelegatedTenantForPage,
   getCurrentToken,
@@ -152,6 +153,72 @@ describe('delegated (MSP) routing + tenant enforcement', () => {
   });
 });
 
+describe('delegated (MSP) home-tenant access — member of own tenant + delegated elsewhere', () => {
+  const MANAGED = 'aaaa-1111';
+  const HOME = 'home-9999';
+
+  it('exposes the home tenant via getHomeTenantId (lowercased at the guard)', () => {
+    runWithCaller({ token: 'msp', isGlobalAdmin: false, delegatedTenantIds: [MANAGED], homeTenantId: HOME }, () => {
+      expect(getHomeTenantId()).toBe(HOME);
+      expect(getDelegatedTenantIds()).toEqual([MANAGED]); // home is NOT part of the managed set
+    });
+  });
+
+  it('enforceDelegatedTenant accepts the home tenant in addition to the managed set', () => {
+    runWithCaller({ token: 'msp', isGlobalAdmin: false, delegatedTenantIds: [MANAGED], homeTenantId: HOME }, () => {
+      expect(enforceDelegatedTenant(HOME)).toBe(HOME);
+      expect(enforceDelegatedTenant('HOME-9999')).toBe(HOME); // case-insensitive
+      expect(enforceDelegatedTenant(MANAGED)).toBe(MANAGED);  // managed still works
+    });
+  });
+
+  it('routes a delegated caller reading their HOME tenant to the tenant (member) path', () => {
+    runWithCaller({ token: 'msp', isGlobalAdmin: false, delegatedTenantIds: [MANAGED], homeTenantId: HOME }, () => {
+      // Home tenant → member path (the /api/global/* drill is bounded to the managed set → empty).
+      expect(pickGlobalOrTenantPath(GLOBAL, TENANT, HOME)).toBe(TENANT);
+      // Managed tenant → cross-tenant global path.
+      expect(pickGlobalOrTenantPath(GLOBAL, TENANT, MANAGED)).toBe(GLOBAL);
+      // No effective tenant passed → default cross-tenant routing (unchanged).
+      expect(pickGlobalOrTenantPath(GLOBAL, TENANT)).toBe(GLOBAL);
+    });
+  });
+
+  it('still throws for a tenant that is neither managed nor the home tenant', () => {
+    runWithCaller({ token: 'msp', isGlobalAdmin: false, delegatedTenantIds: [MANAGED], homeTenantId: HOME }, () => {
+      expect(() => enforceDelegatedTenant('cccc-3333')).toThrow(/Not authorized for tenant/);
+    });
+  });
+
+  it('paginates a home-tenant search: a non-global tenant-path nextLink resolves to home (re-selects the tenant path)', () => {
+    runWithCaller({ token: 'msp', isGlobalAdmin: false, delegatedTenantIds: [MANAGED], homeTenantId: HOME }, () => {
+      // Page 2 of a home-tenant search: the backend nextLink is JWT-bound (no tenantId), path is /api/* not /api/global/*.
+      const homeNextLink = '/api/search/sessions?continuation=abc&pageSize=200';
+      const resolved = enforceDelegatedTenantForPage(undefined, homeNextLink);
+      expect(resolved).toBe(HOME);
+      expect(pickGlobalOrTenantPath(GLOBAL, TENANT, resolved)).toBe(TENANT);
+      // A managed-tenant page-2 (global nextLink carrying tenantId) still routes cross-tenant.
+      const managedNextLink = `/api/global/search/sessions?continuation=abc&tenantId=${MANAGED}`;
+      const resolvedManaged = enforceDelegatedTenantForPage(undefined, managedNextLink);
+      expect(resolvedManaged).toBe(MANAGED);
+      expect(pickGlobalOrTenantPath(GLOBAL, TENANT, resolvedManaged)).toBe(GLOBAL);
+    });
+  });
+
+  it('a hand-crafted non-global continuation embedding a foreign tenantId is still rejected (defense in depth)', () => {
+    runWithCaller({ token: 'msp', isGlobalAdmin: false, delegatedTenantIds: [MANAGED], homeTenantId: HOME }, () => {
+      expect(() => enforceDelegatedTenantForPage(undefined, '/api/raw/events?tenantId=cccc-3333')).toThrow(/Not authorized/);
+    });
+  });
+
+  it('without a home tenant in context, the old strict behavior holds (no phantom home access)', () => {
+    runWithCaller({ token: 'msp', isGlobalAdmin: false, delegatedTenantIds: [MANAGED] }, () => {
+      expect(getHomeTenantId()).toBeUndefined();
+      expect(() => enforceDelegatedTenant(HOME)).toThrow(/Not authorized for tenant/);
+      expect(pickGlobalOrTenantPath(GLOBAL, TENANT, HOME)).toBe(GLOBAL); // no home carve-out
+    });
+  });
+});
+
 describe('runWithCaller — context isolation', () => {
   it('keeps concurrent contexts from bleeding into each other', async () => {
     // Interleave two async callers on the event loop; each must continue to see

src/McpServer/autopilot-monitor-mcp/src/access-guard.ts

@@ -492,6 +492,10 @@ export function accessGuard(req: Request, res: Response, next: NextFunction): vo
           isGlobalReader: result.isGlobalReader,
           delegatedTenantIds: result.delegatedTenantIds,
           delegatedRole: result.delegatedRole,
+          // Home tenant from the JWT `tid` (lowercased). Lets a delegated (MSP) admin who is also a member
+          // of their own home tenant keep reading it via the tenant-scoped member path — see client.ts
+          // enforceDelegatedTenant / pickGlobalOrTenantPath. Harmless for GA / plain tenant callers.
+          homeTenantId: claims.tid?.toLowerCase(),
         },
         () => next(),
       );

src/McpServer/autopilot-monitor-mcp/src/client.ts

@@ -58,6 +58,17 @@ interface CallerContext {
   delegatedTenantIds?: string[];
   /** Strongest delegated role ("DelegatedAdmin" | "DelegatedReader"); informational (read-only server). */
   delegatedRole?: string;
+  /**
+   * The caller's home tenant (lowercase JWT `tid`). Set for every caller (harmless for GA / plain tenant
+   * users, who never consult it). Its purpose is the delegated (MSP) case: a delegated caller who is ALSO
+   * a member/operator of their OWN home tenant must keep reading it over MCP. That access is member-based
+   * (JWT-bound `/api/*`), NOT a delegated grant — the home tenant is not in `delegatedTenantIds` and the
+   * `/api/global/*` drill is bounded to the managed set (would return empty for it). So the home tenant is
+   * accepted by `enforceDelegatedTenant` and routed to the tenant-scoped member path by
+   * `pickGlobalOrTenantPath`. The backend is authoritative: a delegated caller who is NOT a member of their
+   * home tenant is simply denied there (MemberRead), so accepting the id here never leaks.
+   */
+  homeTenantId?: string;
 }
 
 const callerStore = new AsyncLocalStorage<CallerContext>();
@@ -114,6 +125,15 @@ export function isDelegated(): boolean {
   return (callerStore.getStore()?.delegatedTenantIds?.length ?? 0) > 0;
 }
 
+/**
+ * The current caller's home tenant (lowercase JWT `tid`), or undefined when no context is active / the
+ * token carried no tid. Used by the delegated (MSP) routing helpers so a delegated admin who is also a
+ * member of their home tenant can still read it via the tenant-scoped member path.
+ */
+export function getHomeTenantId(): string | undefined {
+  return callerStore.getStore()?.homeTenantId;
+}
+
 /**
  * True when the caller may address the cross-tenant `/api/global/*` paths. That is the union of platform
  * scope (GA / read-only Global Reader, who may omit tenantId for an aggregate) and delegated scope (MSP,
@@ -130,8 +150,21 @@ export function hasCrossTenantRouting(): boolean {
  * variant. The same `tenantId` query param is meaningful in both worlds — on `/api/global/*` it filters
  * (and for a delegated caller the backend rescue bounds it to the managed set); on `/api/*` it's
  * informational (backend resolves from JWT).
+ *
+ * `effectiveTenantId` (the already-`enforceDelegatedTenant`-resolved target) carves out ONE exception: a
+ * delegated (MSP) caller reading their OWN home tenant is routed to the tenant-scoped MEMBER path, because
+ * their authorization there is member/operator (JWT-bound `/api/*`), NOT a delegated grant — and the
+ * `/api/global/*` drill is bounded to the managed set, so it would return an EMPTY page for the home
+ * tenant. Omitting the arg preserves the old behavior for every non-home / non-delegated call.
  */
-export function pickGlobalOrTenantPath(globalPath: string, tenantPath: string): string {
+export function pickGlobalOrTenantPath(globalPath: string, tenantPath: string, effectiveTenantId?: string): string {
+  if (
+    isDelegated() &&
+    effectiveTenantId &&
+    effectiveTenantId.toLowerCase() === getHomeTenantId()
+  ) {
+    return tenantPath;
+  }
   return hasCrossTenantRouting() ? globalPath : tenantPath;
 }
 
@@ -147,16 +180,23 @@ export function pickGlobalOrTenantPath(globalPath: string, tenantPath: string):
 export function enforceDelegatedTenant(tenantId?: string): string | undefined {
   if (!isDelegated()) return tenantId;
   const allowed = getDelegatedTenantIds()!; // non-empty when isDelegated()
+  // The caller's own home tenant is an ADDITIONAL valid target: a delegated admin who is also a member of
+  // their home tenant reads it via the member path (see pickGlobalOrTenantPath). It is deliberately NOT in
+  // the managed set (that is other tenants they administer). Accepting it here is safe even for a delegated
+  // caller who is NOT a member — the backend's MemberRead denies them on the tenant path, so no leak.
+  const home = getHomeTenantId();
   const t = (tenantId ?? '').toLowerCase();
   if (!t) {
     throw new Error(
-      'tenantId is required: as a delegated (MSP) user you must name one of your managed tenants. ' +
-      `Managed tenants: ${allowed.join(', ')}`,
+      'tenantId is required: as a delegated (MSP) user you must name the tenant to query. ' +
+      `Managed tenants: ${allowed.join(', ')}` +
+      (home ? `; or your own home tenant: ${home}.` : '.'),
     );
   }
-  if (!allowed.includes(t)) {
+  if (!allowed.includes(t) && t !== home) {
     throw new Error(
-      `Not authorized for tenant ${tenantId}. Your managed tenants: ${allowed.join(', ')}`,
+      `Not authorized for tenant ${tenantId}. Your managed tenants: ${allowed.join(', ')}` +
+      (home ? ` (or your own home tenant ${home}).` : '.'),
     );
   }
   return t;
@@ -185,7 +225,17 @@ function tenantIdFromNextLink(continuation?: string): string | undefined {
  */
 export function enforceDelegatedTenantForPage(tenantId?: string, continuation?: string): string | undefined {
   if (!isDelegated()) return tenantId;
-  return enforceDelegatedTenant(tenantIdFromNextLink(continuation) ?? tenantId);
+  const linkTenant = tenantIdFromNextLink(continuation);
+  // A follow-up page whose continuation is a full backend nextLink to a TENANT-scoped (non-global) path
+  // with NO embedded tenantId is inherently JWT-bound — it can only ever serve the caller's own home
+  // tenant (page 1 already routed there via pickGlobalOrTenantPath). Resolve it TO the home tenant so the
+  // follow-up page re-selects the same tenant path (matching page 1) without a managed-tenant check. A
+  // hand-crafted continuation that DOES embed a tenantId still flows through enforceDelegatedTenant below,
+  // so the defense-in-depth validation is preserved.
+  if (continuation?.startsWith('/api/') && !continuation.startsWith('/api/global/') && !linkTenant) {
+    return getHomeTenantId() ?? tenantId;
+  }
+  return enforceDelegatedTenant(linkTenant ?? tenantId);
 }
 
 /**

src/McpServer/autopilot-monitor-mcp/src/index.ts

@@ -16,7 +16,7 @@ import { validatePrecomputedIndex } from './precomputed-index.js';
 import { buildEventTypeSearchDocs } from './resource-catalog.js';
 import { createOAuthRouter } from './oauth.js';
 import { accessGuard } from './access-guard.js';
-import { hasGlobalScope, isGlobalAdmin, isDelegated, getDelegatedTenantIds } from './client.js';
+import { hasGlobalScope, isGlobalAdmin, isDelegated, getDelegatedTenantIds, getHomeTenantId } from './client.js';
 import { API_BASE_URL } from './config.js';
 
 const __dirname = dirname(fileURLToPath(import.meta.url));
@@ -137,15 +137,17 @@ console.error(`Event-type index ready: ${eventTypeIndex.name} — ${eventTypeInd
 // Reader) sees the cross-tenant scope hint. A normal tenant user gets
 // instructions with no mention of cross-tenant capability at all — the surface
 // is scoped to what they can actually do.
-function buildInstructions(ga: boolean, delegated: boolean, managedTenants: string[]): string {
+function buildInstructions(ga: boolean, delegated: boolean, managedTenants: string[], homeTenantId?: string): string {
   // Delegated (MSP) callers get a tenant-bounded surface: cross-tenant ROUTING, but every query MUST name
-  // one of their managed tenants — no platform aggregate. Spell that out once here (the host surfaces it
-  // per connection) so the model passes tenantId up front instead of discovering it via a tool error.
+  // a tenant — no platform aggregate. Spell that out once here (the host surfaces it per connection) so the
+  // model passes tenantId up front instead of discovering it via a tool error. A delegated admin who is
+  // also a member of their own home tenant may name it too (routed to the member path), so surface it.
   const scopeLine = ga
     ? 'Scope: omit tenantId for cross-tenant queries (platform scope); pass tenantId to scope to one tenant.'
     : delegated
-      ? 'Scope: you are a delegated (MSP) administrator. Every query MUST name one of your managed tenants via ' +
-        `tenantId — there is no cross-tenant aggregate. Your managed tenants: ${managedTenants.join(', ')}.`
+      ? 'Scope: you are a delegated (MSP) administrator. Every query MUST name a tenant via tenantId — there ' +
+        `is no cross-tenant aggregate. Your managed tenants: ${managedTenants.join(', ')}.` +
+        (homeTenantId ? ` If you are a member of your own home tenant (${homeTenantId}), you may query it by naming it too.` : '')
       : 'Scope: all queries are automatically limited to your tenant.';
   return [
     'Autopilot-Monitor is a READ-ONLY telemetry server for Windows Autopilot enrollment sessions.',
@@ -165,10 +167,10 @@ function buildInstructions(ga: boolean, delegated: boolean, managedTenants: stri
  * role: a non-Global-Admin never sees GA-only tools or any cross-tenant / GA
  * wording — reducing both confusion and attack surface.
  */
-function createMcpServer(ga: boolean, strictGa: boolean, delegated: boolean, managedTenants: string[]): McpServer {
+function createMcpServer(ga: boolean, strictGa: boolean, delegated: boolean, managedTenants: string[], homeTenantId?: string): McpServer {
   const s = new McpServer(
     { name: 'Autopilot-Monitor', version: SERVER_VERSION },
-    { instructions: buildInstructions(ga, delegated, managedTenants) },
+    { instructions: buildInstructions(ga, delegated, managedTenants, homeTenantId) },
   );
   registerTools(s, knowledgeBase, eventTypeIndex, ga, strictGa, delegated);
   registerResources(s);
@@ -277,7 +279,10 @@ app.all('/mcp', async (req, res) => {
   const ga = hasGlobalScope();
   const delegated = !ga && isDelegated();
   const managedTenants = delegated ? (getDelegatedTenantIds() ?? []) : [];
-  const server = createMcpServer(ga, isGlobalAdmin(), delegated, managedTenants);
+  // Home tenant is only surfaced to a delegated caller (for the "you may also query your home tenant" hint);
+  // GA / plain tenant users don't need it in their instructions.
+  const homeTenantId = delegated ? getHomeTenantId() : undefined;
+  const server = createMcpServer(ga, isGlobalAdmin(), delegated, managedTenants, homeTenantId);
 
   // Guarantee cleanup once the response is done, even on client disconnect.
   res.on('close', () => {

src/McpServer/autopilot-monitor-mcp/src/tools/admin.ts

@@ -244,7 +244,7 @@ export function registerAdminTools(server: McpServer, ga: boolean, strictGa: boo
         const tenantId = enforceDelegatedTenant(rawTenantId);
         const params: Record<string, string | number | undefined> = { ...rest };
         if (tenantId) params.tenantId = tenantId;
-        const prefix = pickGlobalOrTenantPath('/api/global/metrics', '/api/metrics');
+        const prefix = pickGlobalOrTenantPath('/api/global/metrics', '/api/metrics', tenantId);
         const data = await apiFetch(`${prefix}/geographic${buildQuery(params)}`);
         return toolResultText(data, MAX_RESULT_SIZE_CHARS.small);
       } catch (error: unknown) {
@@ -294,7 +294,7 @@ export function registerAdminTools(server: McpServer, ga: boolean, strictGa: boo
           ...buildGeoLocationParams({ locationKey, country, region, city }),
         };
         if (tenantId) params.tenantId = tenantId;
-        const prefix = pickGlobalOrTenantPath('/api/global/metrics', '/api/metrics');
+        const prefix = pickGlobalOrTenantPath('/api/global/metrics', '/api/metrics', tenantId);
         const data = await apiFetch(`${prefix}/geographic/sessions${buildQuery(params)}`) as
           { success?: boolean; sessions?: unknown[]; totalCount?: number };
 
@@ -448,7 +448,7 @@ export function registerAdminTools(server: McpServer, ga: boolean, strictGa: boo
         // GA → /api/global/metrics/usage (tenantId is a filter); Tenant-Admin → /api/metrics/usage
         // (JWT-scoped; tenantId ignored). Routing by role unlocks the MemberRead tenant endpoint
         // for non-GA callers instead of a blanket 403.
-        const path = pickGlobalOrTenantPath('/api/global/metrics/usage', '/api/metrics/usage');
+        const path = pickGlobalOrTenantPath('/api/global/metrics/usage', '/api/metrics/usage', tenantId);
         const data = await apiFetch(`${path}${buildQuery({ tenantId, days })}`);
         return toolResultText(data, MAX_RESULT_SIZE_CHARS.small);
       } catch (error: unknown) {
@@ -540,7 +540,7 @@ export function registerAdminTools(server: McpServer, ga: boolean, strictGa: boo
       try {
         const { tenantId: rawTenantId, dateFrom, dateTo, action, performedBy, entityType, entityId, pageSize, continuation } = args;
         const tenantId = enforceDelegatedTenantForPage(rawTenantId, continuation);
-        const basePath = pickGlobalOrTenantPath('/api/global/audit/logs', '/api/audit/logs');
+        const basePath = pickGlobalOrTenantPath('/api/global/audit/logs', '/api/audit/logs', tenantId);
         const path = followNextLink(
           basePath,
           { tenantId, dateFrom, dateTo, action, performedBy, entityType, entityId, pageSize },
@@ -686,7 +686,7 @@ export function registerAdminTools(server: McpServer, ga: boolean, strictGa: boo
         const { tenantId: rawTenantId, sessionId, eventType, severity, source, startedAfter, startedBefore, fields, pageSize, continuation } = args;
         const tenantId = enforceDelegatedTenantForPage(rawTenantId, continuation);
         if (eventType) assertKnownEventType(eventType);
-        const basePath = pickGlobalOrTenantPath('/api/global/raw/events', '/api/raw/events');
+        const basePath = pickGlobalOrTenantPath('/api/global/raw/events', '/api/raw/events', tenantId);
         const path = followNextLink(
           basePath,
           { tenantId, sessionId, eventType, severity, source, startedAfter, startedBefore, fields, pageSize },
@@ -755,7 +755,7 @@ export function registerAdminTools(server: McpServer, ga: boolean, strictGa: boo
           imeAgentVersion, imeAgentVersionPrefix, manufacturer, model, enrollmentType, deviceName, osBuild,
           geoCountry, isPreProvisioned, isHybridJoin, isSelfDeployingProfile, fields, pageSize, continuation } = args;
         const tenantId = enforceDelegatedTenantForPage(rawTenantId, continuation);
-        const basePath = pickGlobalOrTenantPath('/api/global/raw/sessions', '/api/raw/sessions');
+        const basePath = pickGlobalOrTenantPath('/api/global/raw/sessions', '/api/raw/sessions', tenantId);
         const path = followNextLink(
           basePath,
           { tenantId, status, startedAfter, startedBefore, serialNumber, agentVersion, agentVersionPrefix,
@@ -917,7 +917,7 @@ export function registerAdminTools(server: McpServer, ga: boolean, strictGa: boo
           ruleType: args.ruleType,
         };
         if (tenantId) params.tenantId = tenantId;
-        const prefix = pickGlobalOrTenantPath('/api/global/metrics', '/api/metrics');
+        const prefix = pickGlobalOrTenantPath('/api/global/metrics', '/api/metrics', tenantId);
         const data = await apiFetch(`${prefix}/rule-stats${buildQuery(params)}`);
         return toolResultText(data, MAX_RESULT_SIZE_CHARS.small);
       } catch (error: unknown) {
@@ -953,7 +953,7 @@ export function registerAdminTools(server: McpServer, ga: boolean, strictGa: boo
       try {
         const { tenantId: rawTenantId, days, topN } = args;
         const tenantId = enforceDelegatedTenant(rawTenantId);
-        const prefix = pickGlobalOrTenantPath('/api/global/metrics/vulnerability', '/api/metrics/vulnerability');
+        const prefix = pickGlobalOrTenantPath('/api/global/metrics/vulnerability', '/api/metrics/vulnerability', tenantId);
         const data = await apiFetch(`${prefix}${buildQuery({ tenantId, days, topN })}`);
         return toolResultText(data, MAX_RESULT_SIZE_CHARS.small);
       } catch (error: unknown) {
@@ -995,7 +995,7 @@ export function registerAdminTools(server: McpServer, ga: boolean, strictGa: boo
         const tenantId = enforceDelegatedTenant(rawTenantId);
         // GA → /api/global/metrics/app (tenantId is a filter); Tenant-Admin → /api/metrics/app
         // (JWT-scoped; tenantId ignored).
-        const path = pickGlobalOrTenantPath('/api/global/metrics/app', '/api/metrics/app');
+        const path = pickGlobalOrTenantPath('/api/global/metrics/app', '/api/metrics/app', tenantId);
         const data = await apiFetch(`${path}${buildQuery({ tenantId, days })}`);
         return toolResultText(data, MAX_RESULT_SIZE_CHARS.small);
       } catch (error: unknown) {
@@ -1093,7 +1093,7 @@ export function registerAdminTools(server: McpServer, ga: boolean, strictGa: boo
           ));
         }
         // Endpoint returns the whole inventory in one shot, so page it client-side.
-        const path = pickGlobalOrTenantPath('/api/vulnerability/software-inventory', '/api/metrics/software-inventory');
+        const path = pickGlobalOrTenantPath('/api/vulnerability/software-inventory', '/api/metrics/software-inventory', tenantId);
         const data = await apiFetch(`${path}${buildQuery({ tenantId })}`);
         return toolResultText(paginateInventory(data, pageSize, continuation), MAX_RESULT_SIZE_CHARS.adminStream);
       } catch (error: unknown) {

src/McpServer/autopilot-monitor-mcp/src/tools/search.ts

@@ -426,7 +426,7 @@ async function fetchSessionEvents(
       // is reserved for the genuine "no keyword maps to any event type" case below.)
       const candidates = ordered.slice(0, MAX_EVENT_TYPE_CANDIDATES);
       const candidatesDropped = ordered.length > candidates.length;
-      const basePath = pickGlobalOrTenantPath('/api/global/raw/events', '/api/raw/events');
+      const basePath = pickGlobalOrTenantPath('/api/global/raw/events', '/api/raw/events', tenantId);
       const { events, truncated, anySucceeded } = await fetchEventsViaIndex(candidates, basePath, tenantId, budget);
       if (anySucceeded) {
         // No event appears in more than one single-type walk, so the only
@@ -444,7 +444,7 @@ async function fetchSessionEvents(
   const searchParams: Record<string, string | number | undefined> = { status: 'Failed', pageSize: LEGACY_FALLBACK_SESSION_CAP };
   if (tenantId) searchParams.tenantId = tenantId;
   const searchQ = buildQuery(searchParams);
-  const searchBase = pickGlobalOrTenantPath('/api/global/search/sessions', '/api/search/sessions');
+  const searchBase = pickGlobalOrTenantPath('/api/global/search/sessions', '/api/search/sessions', tenantId);
   const sessions = await apiFetch(`${searchBase}${searchQ}`) as {
     sessions?: Array<{ sessionId?: string }>;
   };

src/McpServer/autopilot-monitor-mcp/src/tools/sessions.ts

@@ -144,7 +144,7 @@ export function registerSessionTools(server: McpServer, ga: boolean, delegated:
         // continuation nextLink. No-op for GA/Reader/tenant users.
         const tenantId = enforceDelegatedTenantForPage(rawTenantId, continuation);
         // GA → /api/global/search/sessions (tenantId is filter); Tenant-Admin → /api/search/sessions (JWT-bound).
-        const basePath = pickGlobalOrTenantPath('/api/global/search/sessions', '/api/search/sessions');
+        const basePath = pickGlobalOrTenantPath('/api/global/search/sessions', '/api/search/sessions', tenantId);
         // followNextLink handles full nextLink paths verbatim. For first-page calls
         // we still need to layer in deviceProperties as `prop.<key>` query params,
         // which followNextLink doesn't know about — so build the param record and
@@ -202,7 +202,7 @@ export function registerSessionTools(server: McpServer, ga: boolean, delegated:
         // so an empty page never carries a nextLink — no auto-exhaust needed. But validate
         // the type so a typo is a clear error rather than a silent empty result.
         assertKnownEventType(eventType);
-        const basePath = pickGlobalOrTenantPath('/api/global/search/sessions-by-event', '/api/search/sessions-by-event');
+        const basePath = pickGlobalOrTenantPath('/api/global/search/sessions-by-event', '/api/search/sessions-by-event', tenantId);
         const path = followNextLink(
           basePath,
           { eventType, tenantId, pageSize },
@@ -620,7 +620,7 @@ export function registerSessionTools(server: McpServer, ga: boolean, delegated:
         const params: Record<string, string | number | undefined> = { ...rest };
         if (tenantId) params.tenantId = tenantId;
         const q = buildQuery(params);
-        const prefix = pickGlobalOrTenantPath('/api/global/metrics', '/api/metrics');
+        const prefix = pickGlobalOrTenantPath('/api/global/metrics', '/api/metrics', tenantId);
         const [summaryRes, appsRes] = await Promise.allSettled([
           apiFetch(`${prefix}/summary${q}`),
           apiFetch(`${prefix}/app${q}`),
@@ -684,7 +684,7 @@ export function registerSessionTools(server: McpServer, ga: boolean, delegated:
         const tenantId = enforceDelegatedTenantForPage(rawTenantId, continuation);
         // Normalize to canonical upper-case form (schema accepts case-insensitive).
         const normalizedCve = cveId.toUpperCase();
-        const basePath = pickGlobalOrTenantPath('/api/global/search/sessions-by-cve', '/api/search/sessions-by-cve');
+        const basePath = pickGlobalOrTenantPath('/api/global/search/sessions-by-cve', '/api/search/sessions-by-cve', tenantId);
         const path = followNextLink(
           basePath,
           { cveId: normalizedCve, tenantId, minCvssScore, overallRisk, pageSize },

src/McpServer/autopilot-monitor-mcp/src/tools/shared.ts

@@ -58,8 +58,9 @@ export function tenantIdDescription(ga: boolean, delegated: boolean, gaText: str
     // pages behave differently — backend-nextLink pagers re-send tenantId inside the continuation, but
     // offset-based client-side pagers (geo-offset:/inv-offset:) still need it re-passed every page. The
     // per-tool `continuation` arg description owns those mechanics; here we only state the invariant.
-    return 'REQUIRED: name one of YOUR managed tenants (delegated/MSP). There is no cross-tenant aggregate ' +
-      'and no home-tenant default — every query must target a managed tenant.';
+    return 'REQUIRED: name the tenant to query — one of YOUR managed tenants (delegated/MSP), or your own ' +
+      'home tenant if you are a member of it. There is no cross-tenant aggregate and no implicit default — ' +
+      'every query must name a specific tenant.';
   }
   return ga ? gaText : tenantText;
 }