diff --git a/src/proto_alpha/lib_client/client_proto_args.ml b/src/proto_alpha/lib_client/client_proto_args.ml
index ebe0ab1f1..0134ad034 100644
--- a/src/proto_alpha/lib_client/client_proto_args.ml
+++ b/src/proto_alpha/lib_client/client_proto_args.ml
@@ -83,7 +83,7 @@ let () =
     `Permanent
     ~id:"badEndorsementDelayArg"
     ~title:"Bad -endorsement-delay arg"
-    ~description:("invalid priority in -endorsement-delay")
+    ~description:("invalid duration in -endorsement-delay")
     ~pp:(fun ppf literal ->
         Format.fprintf ppf "Bad argument value for -endorsement-delay. Expected an integer, but given '%s'" literal)
     Data_encoding.(obj1 (req "parameter" string))
@@ -236,7 +236,7 @@ let max_priority_arg =
 let fee_threshold_arg =
   arg
     ~long:"fee-threshold"
-    ~placeholder:"threshold"
+    ~placeholder:"amount"
     ~doc:"exclude operations with fees lower than this threshold (in mutez)"
     (parameter (fun _ s ->
          match Tez.of_string s with
@@ -267,7 +267,10 @@ let endorsement_delay_arg =
           production of endorsements for these blocks."
     ~default:"15"
     (parameter (fun _ s ->
-         try return (int_of_string s)
+         try
+           let i = int_of_string s in
+           fail_when (i < 0) (Bad_endorsement_delay s) >>=? fun () ->
+           return (int_of_string s)
          with _ -> fail (Bad_endorsement_delay s)))
 
 let preserved_levels_arg =
diff --git a/src/proto_alpha/lib_delegate/client_baking_forge.ml b/src/proto_alpha/lib_delegate/client_baking_forge.ml
index eadd7291a..6a891b8d7 100644
--- a/src/proto_alpha/lib_delegate/client_baking_forge.ml
+++ b/src/proto_alpha/lib_delegate/client_baking_forge.ml
@@ -33,6 +33,7 @@ open Logging
 (* The index of the different components of the protocol's validation passes *)
 (* TODO: ideally, we would like this to be more abstract and possibly part of
    the protocol, while retaining the generality of lists *)
+(* Hypothesis : we suppose [List.length Proto_alpha.Main.validation_passes = 4] *)
 let endorsements_index = 0
 let votes_index = 1
 let anonymous_index = 2
@@ -253,13 +254,14 @@ let classify_operations
     (ops: Proto_alpha.operation list) =
   Alpha_block_services.live_blocks cctxt ~chain:`Main ~block ()
   >>=? fun live_blocks ->
-  (* Remove operations that are too old for the mempool *)
+  (* Remove operations that are too old *)
   let ops =
     List.filter (fun { shell = { branch } } ->
         Block_hash.Set.mem branch live_blocks
       ) ops
   in
-  let t = Array.make (List.length Proto_alpha.Main.validation_passes) [] in
+  let validation_passes_len = List.length Proto_alpha.Main.validation_passes in
+  let t = Array.make (validation_passes_len + 1) [] in
   List.iter
     (fun (op: Proto_alpha.operation) ->
        List.iter
@@ -278,7 +280,8 @@ let classify_operations
   trim_manager_operations ~max_size ~hard_gas_limit_per_block (List.map fst ordered_operations)
   >>=? fun (desired_manager_operations, overflowing_manager_operations) ->
   t.(managers_index) <- desired_manager_operations ;
-  return @@ (Array.fold_right (fun ops acc -> ops :: acc) t [ overflowing_manager_operations ])
+  t.(validation_passes_len) <- overflowing_manager_operations ;
+  return (Array.to_list t)
 
 let parse (op : Operation.raw) : Operation.packed =
   let protocol_data =
@@ -654,15 +657,14 @@ let fetch_operations
     (cctxt : #Proto_alpha.full)
     ~chain
     state
-    (timestamp, (head, priority, _delegate))
+    (timestamp, (head, _, _delegate))
   =
   Alpha_block_services.Mempool.monitor_operations cctxt ~chain
     ~applied:true ~branch_delayed:true
     ~refused:false ~branch_refused:false () >>=? fun (operation_stream, _stop) ->
-  (* Hypothesis : the first call to the stream returns instantly, even if the mempool is empty *)
+  (* Hypothesis : the first call to the stream returns instantly, even if the mempool is empty. *)
   Lwt_stream.get operation_stream >>= function
-  | None ->
-      (* New head received : should not happen. *)
+  | None -> (* New head received : not supposed to happen. *)
       return_none
   | Some current_mempool ->
       let operations = ref current_mempool in
@@ -745,9 +747,6 @@ let build_block
       -% s Client_keys.Logging.tag name
       -% a timestamp_tag timestamp) >>= fun () ->
 
-  (* (\* Retrieve mempool's pending operations *\)
-   * Alpha_block_services.Mempool.pending_operations cctxt ~chain () >>=? fun mpool -> *)
-
   fetch_operations cctxt ~chain state slot >>=? function
   | None ->
       lwt_log_info Tag.DSL.(fun f ->
@@ -765,7 +764,7 @@ let build_block
         | Some hash -> hash
       in
       if Protocol_hash.(Proto_alpha.hash <> next_version) then
-        (* Delegate validation to shell *)
+        (* Let the shell validate this *)
         shell_prevalidation cctxt ~chain ~block seed_nonce_hash
           (List.sub operations 4) slot
       else
@@ -1018,7 +1017,6 @@ let create
   in
 
   let timeout_k cctxt state () =
-    (* C'est safe ça ? *)
     bake cctxt state >>=? fun () ->
     (* Stopping the timeout and waiting for the next block *)
     state.best_slot <- None ;