No. Mold Breaker allows Shuckle to be an hazard setter which ignores M-Sableye/M-Diance/M-Absol's Magic Bounce even with Toxic/Power Split thus removing some checks to the Mold pokemon and leaving it prone to the others (Bisharp, Rapid Spinners/Defoggers, Taunt and super-effective attacks). I think that a Mold Breaker Sticky Web is something nice to improve the viability of this pokemon. I think about a core with Shuckle+Bisharp (a sort of Deoxis-D+Bisharp when the former was OU).
Shuckle seems interesting, but could you give me more details on what it would do (Slack Off is obvious, but is MB only for getting past M-Sab or am I missing something?)?