Currently there are two main buttons on every tool detail page (example): 'Source code' and 'Browse tool'. It seems like an odd choice to have the 'Source code' as the first button here. People using LTR languages read from left to right and serving 'source code' as the first button instead of 'browse tool' suggests source code is more important than using the tool.
I would suggest at least swapping the buttons around. But i think it would be even better to redesign the 'Source code' button to a small text link instead of a big button.
While working on this issue (and page) anyway: the different parts on this page could really use a bit more margin.