My back end is a simple Python service on GCP that handles HTTP requests from Alexa. The same service also downloads the HN front page from the FireBase mirror and gets summaries from this API:
https://rapidapi.com/textanalysis/api/Text%20Summarization
It's not perfect though, so I may switch to a more expensive summarization API, supplement it with manual summaries, and/or train my own summarization model.
For free-form speech recognition in Alexa, the best option I've seen mentioned on the public Alexa Slack team is using the "SearchQuery" slot. So you'd still have to make a weird catch-all intent that would eat up some of the words (and you wouldn't be able to see them). At the same time, you shouldn't assume that Alexa will give you very good results with such loose constraints. Even in my simple skill it's very bad about confusing certain pairs of words.
As an aside, did you hit 100 enables yet? If so, congrats on the free dot :)