Yes, but it's in the expert FGD version which apparently isn't included with the SDK version of Hammer v4.
Try adding the following text to your FGD file. (Back it up, first.)
//-------------------------------------------------------------------------
// WEAPONS
//-------------------------------------------------------------------------
@BaseClass color(0 0 200) base(Targetname, Angles) = Weapon []
@PointClass base(Weapon) = weapon_knife : "Knife" []
@PointClass base(Weapon) = weapon_mp5navy : "Mp5" []
@PointClass base(Weapon) = weapon_m4a1 : "M4a1" []
@PointClass base(Weapon) = weapon_ak47 : "Ak47" []
@PointClass base(Weapon) = weapon_usp : "Usp" []
@PointClass base(Weapon) = weapon_deagle : "Deagle" []
@PointClass base(Weapon) = weapon_aug : "Steyr Aug" []
@PointClass base(Weapon) = weapon_awp : "AWP" []
@PointClass base(Weapon) = weapon_c4 : "C4 Bomb" []
@PointClass base(Weapon) = weapon_elite : "Elite" []
@PointClass base(Weapon) = weapon_famas : "Famas" []
@PointClass base(Weapon) = weapon_fiveseven : "Fiveseven" []
@PointClass base(Weapon) = weapon_flashbang : "Flash Grenade" []
@PointClass base(Weapon) = weapon_g3sg1 : "G3sg1" []
@PointClass base(Weapon) = weapon_galil : "Gallil" []
@PointClass base(Weapon) = weapon_glock : "Glock" []
@PointClass base(Weapon) = weapon_hegrenade : "HE Granade" []
@PointClass base(Weapon) = weapon_m3 : "M3 Shotgun" []
@PointClass base(Weapon) = weapon_m249 : "M249" []
@PointClass base(Weapon) = weapon_mac10 : "Mac10" []
@PointClass base(Weapon) = weapon_p90 : "P90" []
@PointClass base(Weapon) = weapon_p228 : "P228" []
@PointClass base(Weapon) = weapon_scout : "Scout" []
@PointClass base(Weapon) = weapon_sg550 : "SG 550" []
@PointClass base(Weapon) = weapon_sg552 : "SG 552" []
@PointClass base(Weapon) = weapon_smokegrenade : "Smoke Grenade" []
@PointClass base(Weapon) = weapon_tmp : "TMP" []
@PointClass base(Weapon) = weapon_ump45 : "UMP 45" []
@PointClass base(Weapon) = weapon_xm1014 : "XM 1014 Shotgun" []
@PointClass base(Weapon) = item_kevlar : "Kevlar" []
@PointClass base(Weapon) = item_assaultsuit : "Assault Suit" []
@PointClass base(Weapon) = item_defuser : "Diffuse Kit" []