I just hope his self-esteem actually improves with more of this happening as the story progresses.
The "perpetually low self-esteem dense MC" trope is frustrating, sadly very common and kind of annoying after seeing it over and over again.
Hyperlink to the very short and easy to remember title:
Munou wa Fuyou to Iware "Tokei Tsukai" no Boku wa Shokunin Guild kara Oidasareru mo, Dungeon no Shinbu de Shin mo Chikara ni Kakusei suru
or as people used to call at the start, "Watchmaker's Revenge".
That kid's stealing skill is as absurd as that one from the MC of the clock user manga, that expands the idea of a clock and uses time to do everything he wants...
Although it is, at least physically, indeed a hammerhead dragon, I'm disappointed to see his mind is just of a big dumb lizard.
Dragons are usually the smart ones and the "big dumb lizard" title goes to wyverns.