Does Halo help write the opportunities?

Short answer is Yes.

Slightly longer answer...

Industry, academia and startups speak different languages and use different vocabulary. In the past when companies have posted opportunities with unsatisfactory results, one of the primary reasons was that the requirements were not clear to the scientists. If the requirements are not clear, you're setting yourself up for failure. Therefore, every opportunity on Halo first gets user tested with scientists in the respective field to get feedback and ensure the requirements are crystal clear. We inevitably find ways to clarify language and make improvements to the opportunity. The end result is that sponsors receive far more quality proposals. 

For a real-life example, we user tested and revised an opportunity from PepsiCo that it had posted on its own site for more than a year with demonstrably better results. See PepsiCo case study.