diff --git a/cmd/oras/root/manifest/fetch.go b/cmd/oras/root/manifest/fetch.go
index b8ea03489..46b75d11a 100644
--- a/cmd/oras/root/manifest/fetch.go
+++ b/cmd/oras/root/manifest/fetch.go
@@ -104,7 +104,9 @@ Example - Fetch raw manifest from an OCI layout archive file 'layout.tar':
 
 	cmd.Flags().StringSliceVarP(&opts.mediaTypes, "media-type", "", nil, "accepted media types")
 	cmd.Flags().StringVarP(&opts.outputPath, "output", "o", "", "file `path` to write the fetched manifest to, use - for stdout")
-	cmd.Flags().StringVar(&opts.Template, "format", "", `Print output using the given Go template.`)
+	cmd.Flags().StringVar(&opts.Template, "format", "", `Format output using a custom template:
+'json':       Print manifest in prettified JSON format
+'$TEMPLATE':  Print output using the given Go template.`)
 	option.ApplyFlags(&opts, cmd.Flags())
 	return oerrors.Command(cmd, &opts.Target)
 }
diff --git a/test/e2e/suite/command/manifest.go b/test/e2e/suite/command/manifest.go
index f7e52ad01..bf3579e64 100644
--- a/test/e2e/suite/command/manifest.go
+++ b/test/e2e/suite/command/manifest.go
@@ -97,6 +97,15 @@ var _ = Describe("ORAS beginners:", func() {
 			It("should fail with suggestion if no tag or digest is provided", func() {
 				ORAS("manifest", "fetch", RegistryRef(ZOTHost, ImageRepo, "")).ExpectFailure().MatchErrKeyWords("Error:", "no tag or digest specified", "oras manifest fetch [flags] <name>{:<tag>|@<digest>}", "Please specify a reference").Exec()
 			})
+
+			It("should fail if stdout is used inpropriately", func() {
+				ORAS("manifest", "fetch", RegistryRef(ZOTHost, ImageRepo, foobar.Tag), "--output", "-", "--format", "test").
+					ExpectFailure().Exec()
+				ORAS("manifest", "fetch", RegistryRef(ZOTHost, ImageRepo, foobar.Tag), "--descriptor", "--format", "test").
+					ExpectFailure().Exec()
+				ORAS("manifest", "fetch", RegistryRef(ZOTHost, ImageRepo, foobar.Tag), "--output", "-", "--descriptor").
+					ExpectFailure().Exec()
+			})
 		})
 
 		When("running `manifest delete`", func() {