Add type-level help text support to ArgParser generator (#457)

The ArgumentHelpText attribute can now be applied to the record type itself
to display help text at the top of the --help output, before field descriptions.
This enables better documentation of command-line argument parsers.

Features:
- Type-level help text appears before argument list
- Multiline help text is supported
- Backward compatible with existing code
- Help text appears in both --help and error messages

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-authored-by: Claude <noreply@anthropic.com>

ConsumePlugin/Args.fs

@@ -235,3 +235,27 @@ type FlagsIntoPositionalArgs' =
         [<PositionalArgs false>]
         DontGrabEverything : string list
     }
+
+[<ArgParser>]
+[<ArgumentHelpText "Parse command-line arguments for a basic configuration. This help text appears before the argument list.">]
+type WithTypeHelp =
+    {
+        [<ArgumentHelpText "The configuration file path">]
+        ConfigFile : string
+        [<ArgumentHelpText "Enable verbose output">]
+        Verbose : bool
+        Port : int
+    }
+
+[<ArgParser>]
+[<ArgumentHelpText "This is a multiline help text example.
+It spans multiple lines to test that multiline strings work correctly.
+You can use this to provide detailed documentation for your argument parser.">]
+type WithMultilineTypeHelp =
+    {
+        [<ArgumentHelpText "Input file to process">]
+        InputFile : string
+        [<ArgumentHelpText "Output directory">]
+        OutputDir : string
+        Force : bool
+    }

ConsumePlugin/GeneratedArgs.fs

@@ -4346,3 +4346,438 @@ module FlagsIntoPositionalArgs'ArgParse =
 
         static member parse (args : string list) : FlagsIntoPositionalArgs' =
             FlagsIntoPositionalArgs'.parse' (System.Environment.GetEnvironmentVariable >> Option.ofObj) args
+namespace ConsumePlugin
+
+open System
+open System.IO
+open WoofWare.Myriad.Plugins
+
+/// Methods to parse arguments for the type WithTypeHelp
+[<RequireQualifiedAccess ; CompilationRepresentation(CompilationRepresentationFlags.ModuleSuffix)>]
+module WithTypeHelp =
+    type private ParseState_WithTypeHelp =
+        /// Ready to consume a key or positional arg
+        | AwaitingKey
+        /// Waiting to receive a value for the key we've already consumed
+        | AwaitingValue of key : string
+
+    let parse' (getEnvironmentVariable : string -> string option) (args : string list) : WithTypeHelp =
+        let ArgParser_errors = ResizeArray ()
+
+        let helpText () =
+            [
+                "Parse command-line arguments for a basic configuration. This help text appears before the argument list."
+                ""
+
+                (sprintf
+                    "%s  string%s%s"
+                    (sprintf "--%s" "config-file")
+                    ""
+                    (sprintf " : %s" ("The configuration file path")))
+
+                (sprintf "%s  bool%s%s" (sprintf "--%s" "verbose") "" (sprintf " : %s" ("Enable verbose output")))
+                (sprintf "%s  int32%s%s" (sprintf "--%s" "port") "" "")
+            ]
+            |> String.concat "\n"
+
+        let parser_LeftoverArgs : string ResizeArray = ResizeArray ()
+        let mutable arg_0 : string option = None
+        let mutable arg_1 : bool option = None
+        let mutable arg_2 : int option = None
+
+        /// Processes the key-value pair, returning Error if no key was matched.
+        /// If the key is an arg which can have arity 1, but throws when consuming that arg, we return Error(<the message>).
+        /// This can nevertheless be a successful parse, e.g. when the key may have arity 0.
+        let processKeyValue (key : string) (value : string) : Result<unit, string option> =
+            if System.String.Equals (key, sprintf "--%s" "port", System.StringComparison.OrdinalIgnoreCase) then
+                match arg_2 with
+                | Some x ->
+                    sprintf
+                        "Argument '%s' was supplied multiple times: %s and %s"
+                        (sprintf "--%s" "port")
+                        (x.ToString ())
+                        (value.ToString ())
+                    |> ArgParser_errors.Add
+
+                    Ok ()
+                | None ->
+                    try
+                        arg_2 <- value |> (fun x -> System.Int32.Parse x) |> Some
+                        Ok ()
+                    with _ as exc ->
+                        exc.Message |> Some |> Error
+            else if System.String.Equals (key, sprintf "--%s" "verbose", System.StringComparison.OrdinalIgnoreCase) then
+                match arg_1 with
+                | Some x ->
+                    sprintf
+                        "Argument '%s' was supplied multiple times: %s and %s"
+                        (sprintf "--%s" "verbose")
+                        (x.ToString ())
+                        (value.ToString ())
+                    |> ArgParser_errors.Add
+
+                    Ok ()
+                | None ->
+                    try
+                        arg_1 <- value |> (fun x -> System.Boolean.Parse x) |> Some
+                        Ok ()
+                    with _ as exc ->
+                        exc.Message |> Some |> Error
+            else if
+                System.String.Equals (key, sprintf "--%s" "config-file", System.StringComparison.OrdinalIgnoreCase)
+            then
+                match arg_0 with
+                | Some x ->
+                    sprintf
+                        "Argument '%s' was supplied multiple times: %s and %s"
+                        (sprintf "--%s" "config-file")
+                        (x.ToString ())
+                        (value.ToString ())
+                    |> ArgParser_errors.Add
+
+                    Ok ()
+                | None ->
+                    try
+                        arg_0 <- value |> (fun x -> x) |> Some
+                        Ok ()
+                    with _ as exc ->
+                        exc.Message |> Some |> Error
+            else
+                Error None
+
+        /// Returns false if we didn't set a value.
+        let setFlagValue (key : string) : bool =
+            if System.String.Equals (key, sprintf "--%s" "verbose", System.StringComparison.OrdinalIgnoreCase) then
+                match arg_1 with
+                | Some x ->
+                    sprintf "Flag '%s' was supplied multiple times" (sprintf "--%s" "verbose")
+                    |> ArgParser_errors.Add
+
+                    true
+                | None ->
+                    arg_1 <- true |> Some
+                    true
+            else
+                false
+
+        let rec go (state : ParseState_WithTypeHelp) (args : string list) =
+            match args with
+            | [] ->
+                match state with
+                | ParseState_WithTypeHelp.AwaitingKey -> ()
+                | ParseState_WithTypeHelp.AwaitingValue key ->
+                    if setFlagValue key then
+                        ()
+                    else
+                        sprintf
+                            "Trailing argument %s had no value. Use a double-dash to separate positional args from key-value args."
+                            key
+                        |> ArgParser_errors.Add
+            | "--" :: rest -> parser_LeftoverArgs.AddRange (rest |> Seq.map (fun x -> x))
+            | arg :: args ->
+                match state with
+                | ParseState_WithTypeHelp.AwaitingKey ->
+                    if arg.StartsWith ("--", System.StringComparison.Ordinal) then
+                        if arg = "--help" then
+                            helpText () |> failwithf "Help text requested.\n%s"
+                        else
+                            let equals = arg.IndexOf (char 61)
+
+                            if equals < 0 then
+                                args |> go (ParseState_WithTypeHelp.AwaitingValue arg)
+                            else
+                                let key = arg.[0 .. equals - 1]
+                                let value = arg.[equals + 1 ..]
+
+                                match processKeyValue key value with
+                                | Ok () -> go ParseState_WithTypeHelp.AwaitingKey args
+                                | Error x ->
+                                    match x with
+                                    | None ->
+                                        failwithf "Unable to process argument %s as key %s and value %s" arg key value
+                                    | Some msg ->
+                                        sprintf "%s (at arg %s)" msg arg |> ArgParser_errors.Add
+                                        go ParseState_WithTypeHelp.AwaitingKey args
+                    else
+                        arg |> (fun x -> x) |> parser_LeftoverArgs.Add
+                        go ParseState_WithTypeHelp.AwaitingKey args
+                | ParseState_WithTypeHelp.AwaitingValue key ->
+                    match processKeyValue key arg with
+                    | Ok () -> go ParseState_WithTypeHelp.AwaitingKey args
+                    | Error exc ->
+                        if setFlagValue key then
+                            go ParseState_WithTypeHelp.AwaitingKey (arg :: args)
+                        else
+                            match exc with
+                            | None ->
+                                failwithf "Unable to process supplied arg %s. Help text follows.\n%s" key (helpText ())
+                            | Some msg -> msg |> ArgParser_errors.Add
+
+        go ParseState_WithTypeHelp.AwaitingKey args
+
+        let parser_LeftoverArgs =
+            if 0 = parser_LeftoverArgs.Count then
+                ()
+            else
+                parser_LeftoverArgs
+                |> String.concat " "
+                |> sprintf "There were leftover args: %s"
+                |> ArgParser_errors.Add
+
+                Unchecked.defaultof<_>
+
+        let arg_0 =
+            match arg_0 with
+            | None ->
+                sprintf "Required argument '%s' received no value" (sprintf "--%s" "config-file")
+                |> ArgParser_errors.Add
+
+                Unchecked.defaultof<_>
+            | Some x -> x
+
+        let arg_1 =
+            match arg_1 with
+            | None ->
+                sprintf "Required argument '%s' received no value" (sprintf "--%s" "verbose")
+                |> ArgParser_errors.Add
+
+                Unchecked.defaultof<_>
+            | Some x -> x
+
+        let arg_2 =
+            match arg_2 with
+            | None ->
+                sprintf "Required argument '%s' received no value" (sprintf "--%s" "port")
+                |> ArgParser_errors.Add
+
+                Unchecked.defaultof<_>
+            | Some x -> x
+
+        if 0 = ArgParser_errors.Count then
+            {
+                ConfigFile = arg_0
+                Port = arg_2
+                Verbose = arg_1
+            }
+        else
+            ArgParser_errors |> String.concat "\n" |> failwithf "Errors during parse!\n%s"
+
+    let parse (args : string list) : WithTypeHelp =
+        parse' (System.Environment.GetEnvironmentVariable >> Option.ofObj) args
+namespace ConsumePlugin
+
+open System
+open System.IO
+open WoofWare.Myriad.Plugins
+
+/// Methods to parse arguments for the type WithMultilineTypeHelp
+[<RequireQualifiedAccess ; CompilationRepresentation(CompilationRepresentationFlags.ModuleSuffix)>]
+module WithMultilineTypeHelp =
+    type private ParseState_WithMultilineTypeHelp =
+        /// Ready to consume a key or positional arg
+        | AwaitingKey
+        /// Waiting to receive a value for the key we've already consumed
+        | AwaitingValue of key : string
+
+    let parse' (getEnvironmentVariable : string -> string option) (args : string list) : WithMultilineTypeHelp =
+        let ArgParser_errors = ResizeArray ()
+
+        let helpText () =
+            [
+                "This is a multiline help text example.
+It spans multiple lines to test that multiline strings work correctly.
+You can use this to provide detailed documentation for your argument parser."
+
+                ""
+                (sprintf "%s  string%s%s" (sprintf "--%s" "input-file") "" (sprintf " : %s" ("Input file to process")))
+                (sprintf "%s  string%s%s" (sprintf "--%s" "output-dir") "" (sprintf " : %s" ("Output directory")))
+                (sprintf "%s  bool%s%s" (sprintf "--%s" "force") "" "")
+            ]
+            |> String.concat "\n"
+
+        let parser_LeftoverArgs : string ResizeArray = ResizeArray ()
+        let mutable arg_0 : string option = None
+        let mutable arg_1 : string option = None
+        let mutable arg_2 : bool option = None
+
+        /// Processes the key-value pair, returning Error if no key was matched.
+        /// If the key is an arg which can have arity 1, but throws when consuming that arg, we return Error(<the message>).
+        /// This can nevertheless be a successful parse, e.g. when the key may have arity 0.
+        let processKeyValue (key : string) (value : string) : Result<unit, string option> =
+            if System.String.Equals (key, sprintf "--%s" "force", System.StringComparison.OrdinalIgnoreCase) then
+                match arg_2 with
+                | Some x ->
+                    sprintf
+                        "Argument '%s' was supplied multiple times: %s and %s"
+                        (sprintf "--%s" "force")
+                        (x.ToString ())
+                        (value.ToString ())
+                    |> ArgParser_errors.Add
+
+                    Ok ()
+                | None ->
+                    try
+                        arg_2 <- value |> (fun x -> System.Boolean.Parse x) |> Some
+                        Ok ()
+                    with _ as exc ->
+                        exc.Message |> Some |> Error
+            else if
+                System.String.Equals (key, sprintf "--%s" "output-dir", System.StringComparison.OrdinalIgnoreCase)
+            then
+                match arg_1 with
+                | Some x ->
+                    sprintf
+                        "Argument '%s' was supplied multiple times: %s and %s"
+                        (sprintf "--%s" "output-dir")
+                        (x.ToString ())
+                        (value.ToString ())
+                    |> ArgParser_errors.Add
+
+                    Ok ()
+                | None ->
+                    try
+                        arg_1 <- value |> (fun x -> x) |> Some
+                        Ok ()
+                    with _ as exc ->
+                        exc.Message |> Some |> Error
+            else if
+                System.String.Equals (key, sprintf "--%s" "input-file", System.StringComparison.OrdinalIgnoreCase)
+            then
+                match arg_0 with
+                | Some x ->
+                    sprintf
+                        "Argument '%s' was supplied multiple times: %s and %s"
+                        (sprintf "--%s" "input-file")
+                        (x.ToString ())
+                        (value.ToString ())
+                    |> ArgParser_errors.Add
+
+                    Ok ()
+                | None ->
+                    try
+                        arg_0 <- value |> (fun x -> x) |> Some
+                        Ok ()
+                    with _ as exc ->
+                        exc.Message |> Some |> Error
+            else
+                Error None
+
+        /// Returns false if we didn't set a value.
+        let setFlagValue (key : string) : bool =
+            if System.String.Equals (key, sprintf "--%s" "force", System.StringComparison.OrdinalIgnoreCase) then
+                match arg_2 with
+                | Some x ->
+                    sprintf "Flag '%s' was supplied multiple times" (sprintf "--%s" "force")
+                    |> ArgParser_errors.Add
+
+                    true
+                | None ->
+                    arg_2 <- true |> Some
+                    true
+            else
+                false
+
+        let rec go (state : ParseState_WithMultilineTypeHelp) (args : string list) =
+            match args with
+            | [] ->
+                match state with
+                | ParseState_WithMultilineTypeHelp.AwaitingKey -> ()
+                | ParseState_WithMultilineTypeHelp.AwaitingValue key ->
+                    if setFlagValue key then
+                        ()
+                    else
+                        sprintf
+                            "Trailing argument %s had no value. Use a double-dash to separate positional args from key-value args."
+                            key
+                        |> ArgParser_errors.Add
+            | "--" :: rest -> parser_LeftoverArgs.AddRange (rest |> Seq.map (fun x -> x))
+            | arg :: args ->
+                match state with
+                | ParseState_WithMultilineTypeHelp.AwaitingKey ->
+                    if arg.StartsWith ("--", System.StringComparison.Ordinal) then
+                        if arg = "--help" then
+                            helpText () |> failwithf "Help text requested.\n%s"
+                        else
+                            let equals = arg.IndexOf (char 61)
+
+                            if equals < 0 then
+                                args |> go (ParseState_WithMultilineTypeHelp.AwaitingValue arg)
+                            else
+                                let key = arg.[0 .. equals - 1]
+                                let value = arg.[equals + 1 ..]
+
+                                match processKeyValue key value with
+                                | Ok () -> go ParseState_WithMultilineTypeHelp.AwaitingKey args
+                                | Error x ->
+                                    match x with
+                                    | None ->
+                                        failwithf "Unable to process argument %s as key %s and value %s" arg key value
+                                    | Some msg ->
+                                        sprintf "%s (at arg %s)" msg arg |> ArgParser_errors.Add
+                                        go ParseState_WithMultilineTypeHelp.AwaitingKey args
+                    else
+                        arg |> (fun x -> x) |> parser_LeftoverArgs.Add
+                        go ParseState_WithMultilineTypeHelp.AwaitingKey args
+                | ParseState_WithMultilineTypeHelp.AwaitingValue key ->
+                    match processKeyValue key arg with
+                    | Ok () -> go ParseState_WithMultilineTypeHelp.AwaitingKey args
+                    | Error exc ->
+                        if setFlagValue key then
+                            go ParseState_WithMultilineTypeHelp.AwaitingKey (arg :: args)
+                        else
+                            match exc with
+                            | None ->
+                                failwithf "Unable to process supplied arg %s. Help text follows.\n%s" key (helpText ())
+                            | Some msg -> msg |> ArgParser_errors.Add
+
+        go ParseState_WithMultilineTypeHelp.AwaitingKey args
+
+        let parser_LeftoverArgs =
+            if 0 = parser_LeftoverArgs.Count then
+                ()
+            else
+                parser_LeftoverArgs
+                |> String.concat " "
+                |> sprintf "There were leftover args: %s"
+                |> ArgParser_errors.Add
+
+                Unchecked.defaultof<_>
+
+        let arg_0 =
+            match arg_0 with
+            | None ->
+                sprintf "Required argument '%s' received no value" (sprintf "--%s" "input-file")
+                |> ArgParser_errors.Add
+
+                Unchecked.defaultof<_>
+            | Some x -> x
+
+        let arg_1 =
+            match arg_1 with
+            | None ->
+                sprintf "Required argument '%s' received no value" (sprintf "--%s" "output-dir")
+                |> ArgParser_errors.Add
+
+                Unchecked.defaultof<_>
+            | Some x -> x
+
+        let arg_2 =
+            match arg_2 with
+            | None ->
+                sprintf "Required argument '%s' received no value" (sprintf "--%s" "force")
+                |> ArgParser_errors.Add
+
+                Unchecked.defaultof<_>
+            | Some x -> x
+
+        if 0 = ArgParser_errors.Count then
+            {
+                Force = arg_2
+                InputFile = arg_0
+                OutputDir = arg_1
+            }
+        else
+            ArgParser_errors |> String.concat "\n" |> failwithf "Errors during parse!\n%s"
+
+    let parse (args : string list) : WithMultilineTypeHelp =
+        parse' (System.Environment.GetEnvironmentVariable >> Option.ofObj) args

WoofWare.Myriad.Plugins.Attributes/ArgParserAttributes.fs

@@ -62,8 +62,10 @@ type ArgumentDefaultFunctionAttribute () =
 type ArgumentDefaultEnvironmentVariableAttribute (envVar : string) =
     inherit Attribute ()
 
-/// Attribute indicating that this field shall have the given help text, when `--help` is invoked
+/// Attribute indicating that this field or type shall have the given help text, when `--help` is invoked
 /// or when a parse error causes us to print help text.
+/// When applied to a record type, the help text appears at the top of the help output, before the field descriptions.
+/// When applied to a field, the help text appears next to that field's description.
 type ArgumentHelpTextAttribute (helpText : string) =
     inherit Attribute ()
 

WoofWare.Myriad.Plugins.Test/TestArgParser/TestArgParser.fs

@@ -444,7 +444,7 @@ Required argument '--exact' received no value"""
         ]
         |> List.map TestCaseData
 
-    [<TestCaseSource(nameof (boolCases))>]
+    [<TestCaseSource(nameof boolCases)>]
     let ``Bool env vars can be populated`` (envValue : string, boolValue : bool) =
         let getEnvVar (s : string) =
             s |> shouldEqual "CONSUMEPLUGIN_THINGS"
@@ -704,3 +704,87 @@ Required argument '--exact' received no value"""
         // Again, we don't try to detect that the user has missed out the desired argument to `--a`.
         exc.Message
         |> shouldEqual """Unable to process argument --c=hi as key --c and value hi"""
+
+    [<Test>]
+    let ``Type-level help text appears in help output`` () =
+        let getEnvVar (_ : string) = None
+
+        let exc =
+            Assert.Throws<exn> (fun () -> WithTypeHelp.parse' getEnvVar [ "--help" ] |> ignore<WithTypeHelp>)
+
+        exc.Message
+        |> shouldContainText
+            "Parse command-line arguments for a basic configuration. This help text appears before the argument list."
+
+        exc.Message
+        |> shouldContainText "--config-file  string : The configuration file path"
+
+        exc.Message |> shouldContainText "--verbose  bool : Enable verbose output"
+        exc.Message |> shouldContainText "--port  int32"
+
+    [<Test>]
+    let ``Type-level help text appears before field help`` () =
+        let getEnvVar (_ : string) = None
+
+        let exc =
+            Assert.Throws<exn> (fun () -> WithTypeHelp.parse' getEnvVar [ "--help" ] |> ignore<WithTypeHelp>)
+
+        // Verify that the type help appears before the field help
+        let typeHelpIndex =
+            exc.Message.IndexOf "Parse command-line arguments for a basic configuration"
+
+        let fieldHelpIndex = exc.Message.IndexOf "--config-file"
+
+        typeHelpIndex |> shouldBeSmallerThan fieldHelpIndex
+
+    [<Test>]
+    let ``Multiline type-level help text works`` () =
+        let getEnvVar (_ : string) = None
+
+        let exc =
+            Assert.Throws<exn> (fun () ->
+                WithMultilineTypeHelp.parse' getEnvVar [ "--help" ]
+                |> ignore<WithMultilineTypeHelp>
+            )
+
+        exc.Message |> shouldContainText "This is a multiline help text example."
+
+        exc.Message
+        |> shouldContainText "It spans multiple lines to test that multiline strings work correctly."
+
+        exc.Message
+        |> shouldContainText "You can use this to provide detailed documentation for your argument parser."
+
+        exc.Message |> shouldContainText "--input-file  string : Input file to process"
+        exc.Message |> shouldContainText "--output-dir  string : Output directory"
+        exc.Message |> shouldContainText "--force  bool"
+
+    [<Test>]
+    let ``Type-level help text appears in error messages`` () =
+        let getEnvVar (_ : string) = None
+
+        let exc =
+            Assert.Throws<exn> (fun () ->
+                WithTypeHelp.parse' getEnvVar [ "--unknown-arg" ; "value" ]
+                |> ignore<WithTypeHelp>
+            )
+
+        // Verify that the type help appears in error messages too
+        exc.Message
+        |> shouldContainText
+            "Parse command-line arguments for a basic configuration. This help text appears before the argument list."
+
+        exc.Message |> shouldContainText "--config-file"
+
+    [<Test>]
+    let ``Types without type-level help still work`` () =
+        let getEnvVar (_ : string) = None
+
+        let exc =
+            Assert.Throws<exn> (fun () -> Basic.parse' getEnvVar [ "--help" ] |> ignore<Basic>)
+
+        // Should not contain any type-level help, just the field help
+        exc.Message |> shouldContainText "--foo  int32 : This is a foo!"
+        exc.Message |> shouldContainText "--bar  string"
+        // Make sure there's no extra blank line at the beginning
+        exc.Message.StartsWith '\n' |> shouldEqual false

WoofWare.Myriad.Plugins/ArgParserGenerator.fs

@@ -769,6 +769,7 @@ module internal ArgParserGenerator =
 
     /// let helpText : string = ...
     let private helpText
+        (typeHelp : SynExpr option)
         (typeName : Ident)
         (positional : ParseFunctionPositional option)
         (args : ParseFunctionNonPositional list)
@@ -850,12 +851,24 @@ module internal ArgParserGenerator =
             |> SynExpr.applyTo helpText
             |> SynExpr.paren
 
+        let fieldHelp =
             args
             |> List.map (toPrintable describeNonPositional)
             |> fun l ->
                 match positional with
                 | None -> l
                 | Some pos -> l @ [ toPrintable describePositional pos ]
+
+        let allHelp =
+            match typeHelp with
+            | Some helpExpr ->
+                // Prepend type help, followed by blank line, then field help
+                [ helpExpr ; SynExpr.CreateConst "" ] @ fieldHelp
+            | None ->
+                // No type help, just field help
+                fieldHelp
+
+        allHelp
         |> SynExpr.listLiteral
         |> SynExpr.pipeThroughFunction (
             SynExpr.applyFunction (SynExpr.createLongIdent [ "String" ; "concat" ]) (SynExpr.CreateConst @"\n")
@@ -1560,6 +1573,7 @@ module internal ArgParserGenerator =
 
     /// Takes a single argument, `args : string list`, and returns something of the type indicated by `recordType`.
     let createRecordParse
+        (typeHelpText : SynExpr option)
         (parseState : Ident)
         (flagDus : FlagDu list)
         (ambientRecords : RecordType list)
@@ -1626,7 +1640,7 @@ module internal ArgParserGenerator =
             |> SynExpr.applyTo (SynExpr.CreateConst ())
             |> SynBinding.basic [ argParseErrors ] []
 
-        let helpText = helpText recordType.Name pos nonPos
+        let helpText = helpText typeHelpText recordType.Name pos nonPos
 
         let bindings = errorCollection :: helpText :: bindings
 
@@ -1923,14 +1937,25 @@ module internal ArgParserGenerator =
                 | _ -> None
             )
 
-        let taggedType =
+        let taggedType, typeHelpText =
             match taggedType with
-            | SynTypeDefn.SynTypeDefn (sci,
+            | SynTypeDefn.SynTypeDefn (SynComponentInfo.SynComponentInfo (attributes = attrs) as sci,
                                        SynTypeDefnRepr.Simple (SynTypeDefnSimpleRepr.Record (access, fields, _), _),
                                        smd,
                                        _,
                                        _,
-                                       _) -> RecordType.OfRecord sci smd access fields
+                                       _) ->
+                let typeHelp =
+                    attrs
+                    |> SynAttributes.toAttrs
+                    |> List.tryPick (fun a ->
+                        match (List.last a.TypeName.LongIdent).idText with
+                        | "ArgumentHelpTextAttribute"
+                        | "ArgumentHelpText" -> Some a.ArgExpr
+                        | _ -> None
+                    )
+
+                RecordType.OfRecord sci smd access fields, typeHelp
             | _ -> failwith "[<ArgParser>] currently only supports being placed on records."
 
         let modAttrs, modName =
@@ -1988,7 +2013,7 @@ module internal ArgParserGenerator =
                 |> SynPat.annotateType (SynType.appPostfix "list" SynType.string)
 
             let parsePrime =
-                createRecordParse parseStateIdent flagDus allRecordTypes taggedType
+                createRecordParse typeHelpText parseStateIdent flagDus allRecordTypes taggedType
                 |> SynBinding.basic
                     [ Ident.create "parse'" ]
                     [