parameter is set to be with maximum length of 125
symbols. This is the limit in the database, so you could not set it to more than that. If, however, you wish to set it to a lower value, you could do that in .../<your_project/Sitefinity/Admin/ControlTemplates/Pages/PagePropertiesInsert.ascx
you could find:
|<asp:TextBox ID="Title" runat="server" MaxLength="125"></asp:TextBox> |
and change the MaxLength
Hope this helps.
the Telerik team