What does Smart Assembly tamper protection do?

Smart Assembly leverages the Windows API (https://learn.microsoft.com/en-us/dotnet/framework/unmanaged-api/strong-naming/strongnamesignatureverificationex-function) to verify tamper-protected assemblies are present and their signatures are unaltered. 

When this is enabled, should any altered assemblies attempt to be loaded by the CLR, the OS will throw a warning that the patterns don't match.
 
Anti-tampering is intended to guard against supply chain attacks, it doesn't prevent binary disassembly.