Do you know you can add more than one Site Owner in Google Webmaster Tools. Site Owners have full control over sites. They can add, remove users and other owners, view and controll all the data of website.
A site owner can also remove your website from search engine. So make sure you are going to give this permission to only trusted person because you would not like to see your website got removed from search engine. I beleive that this option is specially designed for the website partners or SEO companies you are hiring to optimize your website.
How To Add Site Owner In Google Webmaster Tools
Step 1: Login to you Webmaster Tools account.
Step 2: On the Webmaster Tools home page, click the site you want.
Step 3: Click the gear icon , and then click Users & Site Owners.
Step 4: Click Manage Site Owners.
Step 5: In the Verified owners section, click Add an owner.
Step 6: Type the email address of the owner you want to add, and then click Continue.
How To Remove Site Owner In Google Webmaster Tools
Go to Verified owners section as shown above in step 5 and click Unverify next to the owner you want to remove.