diff --git a/docs/agent-skill-sharing-implementation-checklist.md b/docs/agent-skill-sharing-implementation-checklist.md
index fc7095519cc..9b5ad78f8ba 100644
--- a/docs/agent-skill-sharing-implementation-checklist.md
+++ b/docs/agent-skill-sharing-implementation-checklist.md
@@ -1314,7 +1314,9 @@ platform gates below.
       junction coverage remains open.
 - [ ] Test concurrent desktop, headless runtime, CLI, SSH, and recovery attempts.
       The shared transaction core now serializes two simultaneous installs into one installed and
-      one unchanged result, one receipt, and no staging residue; cross-entry-point contention
+      one unchanged result, one receipt, and no staging residue. The host request service also
+      serializes simultaneous download-grant and trusted-local ingress requests with the same
+      guarantees; contention across separate desktop, headless, CLI, SSH, and recovery processes
       remains open.
 - [ ] Test permission and read-only failures, disk exhaustion, cancellation, process termination,
       and host disconnect. Simulated `EACCES` and `ENOSPC` preservation plus lost-response retry are
diff --git a/src/main/skills/skill-install-request-service.test.ts b/src/main/skills/skill-install-request-service.test.ts
index 1645d54c806..1f08fdcc1e1 100644
--- a/src/main/skills/skill-install-request-service.test.ts
+++ b/src/main/skills/skill-install-request-service.test.ts
@@ -81,6 +81,31 @@ describe('executeSkillInstallRequest', () => {
     ).toContain('# Request')
   })
 
+  it('serializes download and trusted-local requests through one destination transaction', async () => {
+    const { root, request, dependencies, archive } = await fixture()
+    const [downloaded, local] = await Promise.all([
+      executeSkillInstallRequest(request, dependencies),
+      executeSkillInstallRequest(
+        {
+          ...request,
+          operationId: 'operation_2',
+          ingress: { kind: 'local-file', path: archive.archivePath }
+        },
+        { ...dependencies, allowTrustedLocalFile: true }
+      )
+    ])
+
+    expect([downloaded.status, local.status].sort()).toEqual(['installed', 'unchanged'])
+    expect(
+      await readdir(join(dependencies.stateDirectory, 'skill-installs', 'receipts'))
+    ).toHaveLength(1)
+    expect(
+      (await readdir(join(root, 'home', '.agents', 'skills'))).filter((name) =>
+        name.includes('.orca-')
+      )
+    ).toEqual([])
+  })
+
   it('rejects local paths at the remote request boundary', async () => {
     const { request, dependencies, archive } = await fixture()
     await expect(