I found some pocket tools that contains some sharp part for cutting seat belt I think, as TSA said no sharp thing are allowed on-bag but the belt cutter isn't something that can harm other, isn't it?
Best of all, the MOCA keychain tool is TSA-friendly so you can take it with you into any airport on all your adventures.
In general, you can check the manufacturer webpages of the specific tool you are considering to see if they make such a claim.
There is no approval scheme for specific products. There are published guidelines which the TSA can (and does) change as they see fit. If the product clearly meets the guidelines in play at the time of inspection, it’s likely, but not guaranteed, to be accepted. TSA agents have the final say. You have no grounds for dispute, despite what some manufacturers imply.
In this case, the question of blade is the most significant. Bladed tools are not permitted for carry on, with some very limited exceptions (scissors under 4 inches from the pivot,at the time of writing).
It is not the manufacturers determination of what constitutes a blade, nor yours, that counts.
So, the rather dull outcome is - if you’re happy to risk losing a $10 tool, you can try. If you’re not, and have checked baggage anyway, pack it in there.
(As an example of manufacturers being potentially misleading, Leatherman lists ‘TSA Approved’ products, whilst the TSA themselves simply state that ‘Leatherman tools aren’t permitted for carry on’. The manufacturer adds a footnote saying they will not pay compensation for confiscation. That suggest they know they cannot stand by their assertion of approval).