diff --git a/src/Pure/Thy/document_marker.ML b/src/Pure/Thy/document_marker.ML
--- a/src/Pure/Thy/document_marker.ML
+++ b/src/Pure/Thy/document_marker.ML
@@ -1,75 +1,80 @@
 (*  Title:      Pure/Thy/document_marker.ML
     Author:     Makarius
 
 Document markers: declarations on the presentation context.
 *)
 
 signature DOCUMENT_MARKER =
 sig
   type marker = Proof.context -> Proof.context
   val setup: binding -> 'a context_parser -> ('a -> marker) -> theory -> theory
   val setup0: binding -> 'a parser -> ('a -> marker) -> theory -> theory
   val evaluate: Input.source -> marker
 end;
 
 structure Document_Marker: DOCUMENT_MARKER =
 struct
 
 (* theory data *)
 
 type marker = Proof.context -> Proof.context;
 
 structure Markers = Theory_Data
 (
   type T = (Token.src -> Proof.context -> Proof.context) Name_Space.table;
   val empty : T = Name_Space.empty_table "document_marker";
   val extend = I;
   val merge = Name_Space.merge_tables;
 );
 
 val get_markers = Markers.get o Proof_Context.theory_of;
 
 fun check ctxt = Name_Space.check (Context.Proof ctxt) (get_markers ctxt);
 
 fun setup name scan body thy =
   let
     fun marker src ctxt =
       let val (x, ctxt') = Token.syntax scan src ctxt
       in body x ctxt' end;
   in thy |> Markers.map (Name_Space.define (Context.Theory thy) true (name, marker) #> #2) end;
 
 fun setup0 name scan = setup name (Scan.lift scan);
 
 
 (* evaluate inner syntax *)
 
 val parse_marker = Parse.token Parse.liberal_name ::: Parse.!!! Parse.args;
 
 fun evaluate input ctxt =
   let
     val pos = Input.pos_of input;
     val _ = Context_Position.report ctxt pos Markup.language_document_marker;
 
     val syms = Input.source_explode input;
     val markers =
       (case Token.read_body (Thy_Header.get_keywords' ctxt) (Parse.list parse_marker) syms of
         SOME res => res
       | NONE => error ("Bad input" ^ Position.here pos));
   in fold (fn src => #2 (check ctxt (Token.name_of_src src)) src) markers ctxt end;
 
 
 (* concrete markers *)
 
 fun meta_data markup arg ctxt =
   (Context_Position.report_text ctxt (Position.thread_data ()) markup arg; ctxt);
 
 val _ =
   Theory.setup
     (setup0 (Binding.make ("tag", \<^here>)) Parse.name Document_Source.update_tags #>
      setup0 (Binding.make ("title", \<^here>)) Parse.embedded (meta_data Markup.meta_title) #>
      setup0 (Binding.make ("creator", \<^here>)) Parse.embedded (meta_data Markup.meta_creator) #>
      setup0 (Binding.make ("contributor", \<^here>)) Parse.embedded (meta_data Markup.meta_contributor) #>
      setup0 (Binding.make ("date", \<^here>)) Parse.embedded (meta_data Markup.meta_date) #>
-     setup0 (Binding.make ("description", \<^here>)) Parse.embedded (meta_data Markup.meta_description));
+     setup0 (Binding.make ("description", \<^here>)) (Parse.input Parse.embedded)
+      (fn source => fn ctxt =>
+        let
+          val (arg, pos) = Input.source_content source;
+          val _ = Context_Position.report ctxt pos Markup.words;
+        in meta_data Markup.meta_description arg ctxt end));
 
 end;