diff --git a/src/services/wikis.ts b/src/services/wikis.ts
index c4c580e..6962f96 100644
--- a/src/services/wikis.ts
+++ b/src/services/wikis.ts
@@ -3,7 +3,10 @@
  * Provides functions to inspect, search, and list OpenProject wiki pages and wiki page links.
  */
 
-import type { OpenProjectClient } from "../client/api-client.ts";
+import {
+  OpenProjectAuthenticationError,
+  type OpenProjectClient,
+} from "../client/api-client.ts";
 import { extractIdFromHref } from "../client/hal-parser.ts";
 import type { HalCollection, HalLink, HalResource } from "../client/types.ts";
 import { resolveClient, resolveProjectId } from "./helper.ts";
@@ -261,6 +264,10 @@ export async function searchWikiPages(
   let cacheMap = wikiPagesCache.get(cacheKey);
   const needsDiscovery = !cacheMap || !discoveredBaseUrls.has(cacheKey) || params?.refreshCache;
 
+  if (params?.refreshCache && cacheMap) {
+    cacheMap.clear();
+  }
+
   if (!cacheMap) {
     cacheMap = new Map<number, WikiPageDetail>();
     wikiPagesCache.set(cacheKey, cacheMap);
@@ -288,8 +295,16 @@ export async function searchWikiPages(
           }
         }
       }
-    } catch {
-      // Ignore errors if wiki_page_links is not supported or accessible
+    } catch (err: unknown) {
+      if (
+        err instanceof OpenProjectAuthenticationError ||
+        (err as { statusCode?: number })?.statusCode === 401 ||
+        (err as { statusCode?: number })?.statusCode === 403 ||
+        (err as { statusCode?: number })?.statusCode === 429
+      ) {
+        throw err;
+      }
+      // Ignore errors if wiki_page_links is not supported or accessible (e.g. 404)
     }
 
     // 2. Sequential probing of IDs 1..MAX_PROBE_ID with consecutive 404 cutoff
@@ -302,8 +317,18 @@ export async function searchWikiPages(
         const pageDetail = await getWikiPage(id, opClient);
         cacheMap.set(id, pageDetail);
         consecutiveMisses = 0;
-      } catch {
-        consecutiveMisses++;
+      } catch (err: unknown) {
+        if (
+          err instanceof OpenProjectAuthenticationError ||
+          (err as { statusCode?: number })?.statusCode === 401 ||
+          (err as { statusCode?: number })?.statusCode === 403 ||
+          (err as { statusCode?: number })?.statusCode === 429
+        ) {
+          throw err;
+        }
+        if ((err as { statusCode?: number })?.statusCode === 404) {
+          consecutiveMisses++;
+        }
         if (consecutiveMisses >= CONSECUTIVE_404_CUTOFF) {
           break;
         }
@@ -316,7 +341,15 @@ export async function searchWikiPages(
         try {
           const pageDetail = await getWikiPage(id, opClient);
           cacheMap.set(id, pageDetail);
-        } catch {
+        } catch (err: unknown) {
+          if (
+            err instanceof OpenProjectAuthenticationError ||
+            (err as { statusCode?: number })?.statusCode === 401 ||
+            (err as { statusCode?: number })?.statusCode === 403 ||
+            (err as { statusCode?: number })?.statusCode === 429
+          ) {
+            throw err;
+          }
           // Ignore missing pages
         }
       }
diff --git a/tests/wikis.test.ts b/tests/wikis.test.ts
index 771ca99..129b567 100644
--- a/tests/wikis.test.ts
+++ b/tests/wikis.test.ts
@@ -1,5 +1,8 @@
 import { describe, expect, test, beforeEach } from "bun:test";
-import { OpenProjectClient } from "../src/client/api-client.ts";
+import {
+  OpenProjectAuthenticationError,
+  OpenProjectClient,
+} from "../src/client/api-client.ts";
 import { runWithContext, type RequestContext } from "../src/context.ts";
 import {
   clearWikiCache,
@@ -382,4 +385,97 @@ describe("Wikis Service", () => {
       expect(searchRes[0]!.title).toBe("Context Wiki");
     });
   });
+
+  test("searchWikiPages re-throws 401 authentication errors during discovery instead of swallowing", async () => {
+    const mockClient = {
+      baseUrl: "http://localhost:8080",
+      get: async (path: string) => {
+        if (path.startsWith("/api/v3/wiki_page_links")) {
+          return { _type: "Collection", total: 0, _embedded: { elements: [] } };
+        }
+        const err = new OpenProjectAuthenticationError("Invalid API key provided");
+        throw err;
+      },
+    } as unknown as OpenProjectClient;
+
+    expect(searchWikiPages({}, mockClient)).rejects.toThrow("Invalid API key provided");
+  });
+
+  test("searchWikiPages re-throws 403 and 429 errors during discovery probe", async () => {
+    const mockForbiddenClient = {
+      baseUrl: "http://localhost:8080",
+      get: async (path: string) => {
+        if (path.startsWith("/api/v3/wiki_page_links")) {
+          return { _type: "Collection", total: 0, _embedded: { elements: [] } };
+        }
+        const err = new Error("Access denied");
+        (err as unknown as { statusCode: number }).statusCode = 403;
+        throw err;
+      },
+    } as unknown as OpenProjectClient;
+
+    expect(searchWikiPages({}, mockForbiddenClient)).rejects.toThrow("Access denied");
+
+    const mockRateLimitClient = {
+      baseUrl: "http://localhost:8080",
+      get: async (path: string) => {
+        if (path.startsWith("/api/v3/wiki_page_links")) {
+          return { _type: "Collection", total: 0, _embedded: { elements: [] } };
+        }
+        const err = new Error("Too many requests");
+        (err as unknown as { statusCode: number }).statusCode = 429;
+        throw err;
+      },
+    } as unknown as OpenProjectClient;
+
+    expect(searchWikiPages({}, mockRateLimitClient)).rejects.toThrow("Too many requests");
+  });
+
+  test("searchWikiPages with refreshCache evicts stale deleted pages from cache", async () => {
+    let page2Exists = true;
+    const mockClient = {
+      baseUrl: "http://localhost:8080",
+      get: async (path: string) => {
+        if (path.startsWith("/api/v3/wiki_page_links")) {
+          return { _type: "Collection", total: 0, _embedded: { elements: [] } };
+        }
+        if (path === "/api/v3/wiki_pages/1") {
+          return {
+            _type: "WikiPage",
+            id: 1,
+            title: "First Page",
+            _links: { project: { href: "/api/v3/projects/1", title: "Demo" } },
+          };
+        }
+        if (path === "/api/v3/wiki_pages/1/attachments") {
+          return { _type: "Collection", total: 0, _embedded: { elements: [] } };
+        }
+        if (path === "/api/v3/wiki_pages/2" && page2Exists) {
+          return {
+            _type: "WikiPage",
+            id: 2,
+            title: "Second Page",
+            _links: { project: { href: "/api/v3/projects/1", title: "Demo" } },
+          };
+        }
+        if (path === "/api/v3/wiki_pages/2/attachments" && page2Exists) {
+          return { _type: "Collection", total: 0, _embedded: { elements: [] } };
+        }
+        const err = new Error("Not found");
+        (err as unknown as { statusCode: number }).statusCode = 404;
+        throw err;
+      },
+    } as unknown as OpenProjectClient;
+
+    const initialResults = await searchWikiPages({}, mockClient);
+    expect(initialResults).toHaveLength(2);
+
+    // Page 2 is subsequently deleted on OpenProject
+    page2Exists = false;
+
+    // Refreshing cache should clear stale page 2 from memory
+    const refreshedResults = await searchWikiPages({ refreshCache: true }, mockClient);
+    expect(refreshedResults).toHaveLength(1);
+    expect(refreshedResults[0]!.id).toBe(1);
+  });
 });