Help should be a direct match.

repl/docs.go

@@ -41,6 +41,10 @@ func (r *REPL) helpBuiltin(ctx context.Context, args ucl.CallArgs) (any, error)
 
 	found := make([]string, 0)
 	for name := range r.commandDocs {
+		if name == cmdName {
+			return NoResults{}, r.showHelpTopic(name)
+		}
+
 		if strings.Contains(name, cmdName) {
 			found = append(found, name)
 		}
@@ -48,8 +52,6 @@ func (r *REPL) helpBuiltin(ctx context.Context, args ucl.CallArgs) (any, error)
 
 	if len(found) == 0 {
 		return nil, errors.New("no help found for topic")
-	} else if len(found) == 1 {
-		return NoResults{}, r.showHelpTopic(found[0])
 	}
 
 	return NoResults{}, r.listHelpTopics(found)

repl/repl.go

@@ -28,17 +28,17 @@ func New(opts ...ucl.InstOption) *REPL {
 	r.inst = ucl.New(instOpts...)
 
 	r.SetCommand("help", r.helpBuiltin, Doc{
-		Brief: "displays help about a command",
-		Usage: "[command]",
+		Brief: "displays help about a command or topic",
+		Usage: "[topic]",
 		Args: []ArgDoc{
-			{Name: "command", Brief: "command to display detailed help for"},
+			{Name: "topic", Brief: "topic to display"},
 		},
 		Detailed: `
 			When used without arguments, 'help' will display the list of known commands,
 			along with a brief description on what each one does.
 
-			When used with an argument, 'help' will display a more detailed explanation
-			of what each command does.
+			If <topic> is a direct match, the contents of <topic> will be displayed.
+			Otherwise, 'help' will list the topics names that match the given substring.
 		`,
 	})