Yocto and extra developement using cross compiling

I guess if it can make problem if we use a Yocto to generate linux environment (kernel, rootfs) and if we develop extra tools & application with linaro chain with cross compiling.
Our situation is :
We use Yocto to generate ROOTFS (with lib/libc-2.20-2014.11.so for example) and we use gcc-linaro-5.2-2015.11-2-x86_64_arm-linux-gnueabihf.tar.xz to have a toolchain to make extra development we need to develop outside yocto space.
The toolchain use libc-2.21.so library and different .H files from ROOTFSSDK we generate from yocto ( libc-2.20-2014.11.so for example).

I work but we guess if it can cause execution error sometime.

Is it a way to use yocto toolchain in our development space ?

Best regards,
Gabriel GRANGE

Currently the best way is to use SDK generated along your yocto image.
You can find instructions here:
http://developer.toradex.com/knowledge-base/linux-sdks