The analysis by @mattdm is very reasonable but it's a little strange that you can't explicitly indicate that your content is released as authorized by a publicly available license document.
Clause  of the license also explicitly requires that you:
... clearly indicate which portions of the work that you are distributing are Open Game Content.
Clause  also requires that you:
... include a copy of this License with every copy of the Open Game Content You Distribute
IANAL, but, based on my understanding of the Open Gaming License Version 1.0a, you must include a copy of the OGL in your content!
Given that the license text includes this (at the end):
- COPYRIGHT NOTICE
Open Game License v 1.0a Copyright 2000, Wizards of the Coast, LLC.
System Reference Document 5.1 Copyright 2016, Wizards of the Coast, Inc.; Authors Mike Mearls, Jeremy Crawford, Chris Perkins, Rodney Thompson, Peter Lee, James Wyatt, Robert J. Schwalb, Bruce R. Cordell, Chris Sims, and Steve Townshend, based on original material by E. Gary Gygax and Dave Arneson.
Also see clause  about copyright:
- Notice of License Copyright: You must update the COPYRIGHT NOTICE portion of this License to include the exact text of the COPYRIGHT NOTICE of any Open Game Content You are copying, modifying or distributing, and You must add the title, the copyright date, and the copyright holder's name to the COPYRIGHT NOTICE of any original Open Game Content you Distribute.
So, if your content uses the SRD, you have to include its copyright notice (see above) in all copies of your content that you distribute.
So, instead of including this in your product's description:
... compatible with Dungeons & Dragons 5th edition
You can include something like:
... released as Open Game Content using the Open Gaming License Version 1.0a. See the copyright notice for details.
The 'compatibility' then will be (at least somewhat) implied by both "Open Game Content" and "Open Gaming License Version 1.0a" and your content's copyright notice, which should include the notice for the SRD itself.
Note though that Open Game Content isn't (necessarily) compatible – you might have modified the rules in the SRD, as you're allowed to do.