Insoluble salts and Gibbs free energy
Yes, this is correct. Assuming that you are talking about solubility in water, it is discussed by JF Liebman, Structural Chemistry, 15, 165 (2004) which needs a subscription to read in full, but much of the key information is given on the first couple of pages which are available as a preview. The relevant thermodynamic quantities (in kJ mol$^{-1}$) for dissolution of one mole in water are given as a table, with AgCl compared with NaCl and KCl:


  $$ \begin{array}{cccc}  &amp; \Delta H &amp; \Delta G &amp; T\Delta S \\ \hline \text{NaCl} &amp; +4 &amp; -9 &amp; +13 \\ \text{KCl} &amp; +17 &amp; -5 &amp; +22 \\ \text{AgCl} &amp; +45 &amp; +37 &amp; +8 \end{array} $$


The author got the original data from NBS Tables of Chemical Thermodynamic Properties.
All the entropy terms are favourable. 
All the enthalpy terms are unfavourable, but the AgCl has a much more unfavourable enthalpy of solution than the alkali metal chlorides, and the
entropy cannot compensate for this. The Ag$^+$ ion is poorly hydrated in solution
compared with Na$^+$ and K$^+$.