No, it's not. Messy kills almost everyone there, but the GM can leave someone(s) alive. In addition, it's loud. It's not just for descriptions, which is what you said.
Cues are recommendations.
• sawed-off (3-harm close reload messy)
This seems like a good "messy" weapon to potentially hit targets in the area that you may not have intended to. Same for grenades and shit. It's also going to destroy some property likely and fuck some bodies up. The loud blast is likely to wake up a whole block.
• crowbar (2-harm hand messy)
Taking a crowbar to someone's face isn't likely to destroy much property or even hit many other people. But, it's certainly going to leave plenty of blood and gore around and might make someone shit their pants. The metal on flesh packing sound might make some peeps wake up nearby too.
Great talk.
Great talk indeed. Clearly there's some confusion about the messy tag.