diff --git a/packages/api/src/agents/__tests__/skills.test.ts b/packages/api/src/agents/__tests__/skills.test.ts
index 87c849fc8f..6d48466921 100644
--- a/packages/api/src/agents/__tests__/skills.test.ts
+++ b/packages/api/src/agents/__tests__/skills.test.ts
@@ -897,6 +897,38 @@ describe('injectSkillCatalog', () => {
     expect(agent.additional_instructions).toContain('desc-my-skill');
   });
 
+  it('warns when a skill description exceeds the catalog entry cap', async () => {
+    const { logger } = await import('@librechat/data-schemas');
+    const warnSpy = jest.spyOn(logger, 'warn');
+    const longDesc = 'x'.repeat(400);
+    const longSkill: PageSkill = {
+      ...makeSkill('long-skill', userObjectId),
+      description: longDesc,
+    };
+    const shortSkill = makeSkill('short-skill', userObjectId);
+    const listSkillsByAccess = buildPager([[longSkill, shortSkill]]);
+    const agent = makeAgent();
+    await injectSkillCatalog(baseParams({ listSkillsByAccess, agent }));
+
+    const truncWarns = warnSpy.mock.calls
+      .map((call) => String(call[0]))
+      .filter((msg) => msg.includes('truncated to'));
+    expect(truncWarns).toHaveLength(1);
+    expect(truncWarns[0]).toContain('"long-skill"');
+    expect(truncWarns[0]).toContain('was 400');
+    /* Short description is not flagged. */
+    expect(
+      warnSpy.mock.calls
+        .map((call) => String(call[0]))
+        .filter((msg) => msg.includes('"short-skill"') && msg.includes('truncated')),
+    ).toHaveLength(0);
+
+    /* The catalog still reaches the model — the warning is additive. */
+    expect(agent.additional_instructions).toContain('long-skill');
+    expect(agent.additional_instructions).toContain('short-skill');
+    warnSpy.mockRestore();
+  });
+
   it('honors a configured maxCatalogSkills below the default hard limit', async () => {
     const first = makeSkill('first-skill', userObjectId);
     const second = makeSkill('second-skill', userObjectId);
diff --git a/packages/api/src/agents/skills.ts b/packages/api/src/agents/skills.ts
index f12fcf75e0..44495f120d 100644
--- a/packages/api/src/agents/skills.ts
+++ b/packages/api/src/agents/skills.ts
@@ -89,6 +89,13 @@ const MIN_SKILL_CATALOG_LIMIT = 1;
 const MAX_CATALOG_PAGES = 10;
 /** Page size used when paginating to fill the active-skill quota. */
 const CATALOG_PAGE_SIZE = 100;
+/**
+ * Per-entry description cap applied by `formatSkillCatalog` before the
+ * catalog is injected into agent context. `@librechat/agents` truncates
+ * silently, so this mirrors the default so we can warn when authors' skill
+ * descriptions will not reach the model verbatim.
+ */
+const SKILL_CATALOG_MAX_ENTRY_CHARS = 250;
 /** Hard ceiling on skill names a model spec can request by config. */
 const MAX_MODEL_SPEC_SKILLS = SKILL_CATALOG_LIMIT;
 /**
@@ -620,9 +627,19 @@ export async function injectSkillCatalog(
    * and those reads would otherwise be impossible.
    */
   if (catalogVisibleSkills.length > 0) {
+    for (const s of catalogVisibleSkills) {
+      if (s.description.length > SKILL_CATALOG_MAX_ENTRY_CHARS) {
+        logger.warn(
+          `[injectSkillCatalog] skill "${s.name}" description truncated to ${SKILL_CATALOG_MAX_ENTRY_CHARS} chars for the model catalog (was ${s.description.length})`,
+        );
+      }
+    }
     const catalog = formatSkillCatalog(
       catalogVisibleSkills.map((s) => ({ name: s.name, description: s.description })),
-      { contextWindowTokens: contextWindowTokens || 200_000 },
+      {
+        contextWindowTokens: contextWindowTokens || 200_000,
+        maxEntryChars: SKILL_CATALOG_MAX_ENTRY_CHARS,
+      },
     );
     if (catalog) {
       agent.additional_instructions = agent.additional_instructions