diff --git a/src/darkleaf/di/core.clj b/src/darkleaf/di/core.clj
index 08641eb..01510a4 100644
--- a/src/darkleaf/di/core.clj
+++ b/src/darkleaf/di/core.clj
@@ -528,11 +528,11 @@
                                    args (map deps arg-keys)]
                                (apply f t args)))
                            (demolish [_ _])
-
                            p/FactoryDescription
                            (description [_]
-                             {::middleware ::update-key
-                              ::target     target}))
+                             {:kind       :middleware
+                              :middleware ::update-key
+                              :target     target}))
           own-registry   (zipmap (cons f-key arg-keys)
                                  (cons f     args))
           target-factory (registry target)]
@@ -630,7 +630,18 @@
     (demolish [_ _])))
 
 (defn- var->0-service [variable]
-  variable)
+  ;; todo: meta ::service
+
+  (reify
+    p/Factory
+    (dependencies [_])
+    (build [_ _]
+      variable)
+    (demolish [_ _])
+    p/FactoryDescription
+    (description [_]
+      {:kind :service
+       :var  variable})))
 
 (defn- var->service [variable]
   (let [deps (dependencies-fn variable)]
@@ -849,8 +860,8 @@
             info          (into {}
                                 (filter (fn [[k v]] (some? v)))
                                 {:key          key
-                                 :dependencies declared-deps
-                                 :meta         (p/description factory)})]
+                                 :dependencies (not-empty declared-deps)
+                                 :description  (not-empty (p/description factory))})]
         (reify p/Factory
           (dependencies [_]
             declared-deps)
diff --git a/test/darkleaf/di/tutorial/x_inspect_test.clj b/test/darkleaf/di/tutorial/x_inspect_test.clj
index 9ce9922..c3d342b 100644
--- a/test/darkleaf/di/tutorial/x_inspect_test.clj
+++ b/test/darkleaf/di/tutorial/x_inspect_test.clj
@@ -14,31 +14,41 @@
           :or {b :default}}]
   :ok)
 
+
+(t/deftest zero-arity-service-test
+  (t/is (= [{:key          ::di/implicit-root
+             :dependencies {`a :required}}
+            {:key         `a
+             :description {:kind :service
+                           :var  #'a}}]
+           (di/inspect `a))))
+
+
+;; todo: name
 (t/deftest ok
   (t/is (= [{:key          ::di/implicit-root
-             :dependencies {`c :required}
-             :meta         {}}
+             :dependencies {`c :required}}
             {:key          `c
-             :dependencies {`a :required `b :optional}
-             :meta         {}}
-            {:key  `a
-             :meta {}}
+             :dependencies {`a :required `b :optional}}
+            {:key         `a
+             :description {:kind :service
+                           :var  #'a}}
             {:key          `b
-             :dependencies {`a :required}
-             :meta         {}}]
+             :dependencies {`a :required}}]
            (di/inspect `c))))
 
-(t/deftest meta-test
+
+(t/deftest update-key-test
   (t/is (= [{:key          ::di/implicit-root,
-             :dependencies {`a :required}
-             :meta         {}}
+             :dependencies {`a :required}}
             {:key          `a,
              :dependencies {`a+di-update-key#0-target :optional,
                             `a+di-update-key#0-f      :optional}
-             :meta         {::di/middleware ::di/update-key
-                            ::di/target     `a}}
-            {:key  `a+di-update-key#0-target
-             :meta {}}
-            {:key  `a+di-update-key#0-f
-             :meta {}}]
+             :description  {:kind       :middleware
+                            :middleware ::di/update-key
+                            :target     `a}}
+            {:key         `a+di-update-key#0-target
+             :description {:kind :service
+                           :var  #'a}}
+            {:key `a+di-update-key#0-f}]
            (di/inspect `a (di/update-key `a str)))))