diff --git a/Library/Homebrew/cmd/desc.rb b/Library/Homebrew/cmd/desc.rb
index 70088f5a99832..b43d9235f8f7b 100644
--- a/Library/Homebrew/cmd/desc.rb
+++ b/Library/Homebrew/cmd/desc.rb
@@ -47,7 +47,7 @@ def run
         end
 
         if search_type.present?
-          if !args.eval_all? && !Homebrew::EnvConfig.eval_all?
+          if !args.eval_all? && !Homebrew::EnvConfig.eval_all? && Homebrew::EnvConfig.no_install_from_api?
             raise UsageError, "`brew desc --search` needs `--eval-all` passed or `HOMEBREW_EVAL_ALL` set!"
           end
 
diff --git a/Library/Homebrew/cmd/search.rb b/Library/Homebrew/cmd/search.rb
index ccdefd308d018..8c6d89a34414f 100644
--- a/Library/Homebrew/cmd/search.rb
+++ b/Library/Homebrew/cmd/search.rb
@@ -70,7 +70,7 @@ def run
         string_or_regex = Search.query_regexp(query)
 
         if args.desc?
-          if !args.eval_all? && !Homebrew::EnvConfig.eval_all?
+          if !args.eval_all? && !Homebrew::EnvConfig.eval_all? && Homebrew::EnvConfig.no_install_from_api?
             raise UsageError, "`brew search --desc` needs `--eval-all` passed or `HOMEBREW_EVAL_ALL` set!"
           end
 
diff --git a/Library/Homebrew/descriptions.rb b/Library/Homebrew/descriptions.rb
index 309ff26cc95e1..967c0d7c22010 100644
--- a/Library/Homebrew/descriptions.rb
+++ b/Library/Homebrew/descriptions.rb
@@ -8,8 +8,10 @@
 # Helper class for printing and searching descriptions.
 class Descriptions
   # Given a regex, find all formulae whose specified fields contain a match.
-  def self.search(string_or_regex, field, cache_store, eval_all = Homebrew::EnvConfig.eval_all?)
-    cache_store.populate_if_empty!(eval_all:)
+  def self.search(string_or_regex, field, cache_store,
+                  eval_all = Homebrew::EnvConfig.eval_all?, cache_store_hash: false)
+
+    cache_store.populate_if_empty!(eval_all:) unless cache_store_hash
 
     results = case field
     when :name
diff --git a/Library/Homebrew/search.rb b/Library/Homebrew/search.rb
index 8c04f4356156d..3e78204d09962 100644
--- a/Library/Homebrew/search.rb
+++ b/Library/Homebrew/search.rb
@@ -22,9 +22,19 @@ def self.search_descriptions(string_or_regex, args, search_type: :desc)
 
       if args.formula? || both
         ohai "Formulae"
-        CacheStoreDatabase.use(:descriptions) do |db|
-          cache_store = DescriptionCacheStore.new(db)
-          Descriptions.search(string_or_regex, search_type, cache_store, eval_all).print
+        if eval_all
+          CacheStoreDatabase.use(:descriptions) do |db|
+            cache_store = DescriptionCacheStore.new(db)
+            Descriptions.search(string_or_regex, search_type, cache_store, eval_all).print
+          end
+        else
+          unofficial = Tap.all.sum { |tap| tap.official? ? 0 : tap.formula_files.size }
+          if unofficial.positive?
+            opoo "Use `--eval-all` to search #{unofficial} additional " \
+                 "#{Utils.pluralize("formula", unofficial, plural: "e")} in third party taps."
+          end
+          descriptions = Homebrew::API::Formula.all_formulae.transform_values { |data| data["desc"] }
+          Descriptions.search(string_or_regex, search_type, descriptions, eval_all, cache_store_hash: true).print
         end
       end
       return if !args.cask? && !both
@@ -32,9 +42,19 @@ def self.search_descriptions(string_or_regex, args, search_type: :desc)
       puts if both
 
       ohai "Casks"
-      CacheStoreDatabase.use(:cask_descriptions) do |db|
-        cache_store = CaskDescriptionCacheStore.new(db)
-        Descriptions.search(string_or_regex, search_type, cache_store, eval_all).print
+      if eval_all
+        CacheStoreDatabase.use(:cask_descriptions) do |db|
+          cache_store = CaskDescriptionCacheStore.new(db)
+          Descriptions.search(string_or_regex, search_type, cache_store, eval_all).print
+        end
+      else
+        unofficial = Tap.all.sum { |tap| tap.official? ? 0 : tap.cask_files.size }
+        if unofficial.positive?
+          opoo "Use `--eval-all` to search #{unofficial} additional " \
+               "#{Utils.pluralize("cask", unofficial)} in third party taps."
+        end
+        descriptions = Homebrew::API::Cask.all_casks.transform_values { |c| [c["name"].join(", "), c["desc"]] }
+        Descriptions.search(string_or_regex, search_type, descriptions, eval_all, cache_store_hash: true).print
       end
     end