Is there any reference to the maximum size for the Name and Description properties of a site collection?
Title / Name: The display name of the site collection. It MUST be less than or equal to 255 characters. If nothing is specified, the site will have a default title of "Team Site".
Check MSDN for other parameters.
If you look on Content Database's table, you will see the below stuff.
Title = nvarchar(255)
Description = nvarchar(max)
nvarchar [ ( n | max ) ] Variable-length Unicode character data. n can be a value from 1 through 4,000. max indicates that the maximum storage size is 2^31-1 bytes. The storage size, in bytes, is two times the number of characters entered + 2 bytes. The data entered can be 0 characters in length. The ISO synonyms for nvarchar are national char varying and national character varying.