Nicole,
Can you elaborate on the deal you've carved out with the existing tenant? Are you providing a Tenant Improvement (TI) allowance to the tenant? OR have you agreed as the Landlord to renovate the space into an event space/beer garden for the existing tenant? Lastly, what is the existing tenant's current business? Is it hospitality/restaurant based? Do they have a good track record in this line of work?
You always need to weigh the economical strength of the tenant versus the tenant specific improvements/build-out that you're considering spending cash on. In other words, if the tenant is weak financially, weak in experience (for this given business focus) and/or weak in both... you need to strongly consider the "what if tenant doesn't make it" scenario. The last thing you want to do is spend a bunch of money of a very tenant specific build-out, have them go out of business and then have to re-lease to a new tenant who will most likely rip out everything related to the last tenant's business concept. Make sense?