MySQL Security permissions
What I am about to say would be rather crazy but entirely possible. Here it goes...

CRAZY SUGGESTION #1


Download the source code for the mysql client
Remove the commands

DESC "table"
SHOW TABLES
SHOW CREATE TABLE "table"

Compile the source
Give your developers access to this special compiled version of the mysql client


CRAZY SUGGESTION #2


Download MySQL Proxy
Program the LUA scripts to ignore

DESC "table"
SHOW TABLES
SHOW CREATE TABLE "table"

Have your developers access DB using MySQL-Proxy-based IP Addresses


EPILOGUE

I would say Give it a Try, but I have never done anything like this before.

Notwithstanding, it would be a brave C/C++ or LUA soul indeed to engage in such an undertaking...