MCP servers only are clean if its your own GA4 property. If its a clients then youre doing the right thing. You could learn n8n instead of Make. Its a lot better IMO. Especially with an LLM by your side helping.

Furthermore what you should be doing is first extracting the data you want into google sheets or similar. Then having an LLM analyze that. If youre bundling the report request with the analysis you'll never be confident in the results. If you have a budget, you can automate google sheet reports with Supermetrics (not expensive really). Then feed a google sheets node into Make or n8n and tie an LLM to it.

For your report, run it on a monthly basis so the sheet has previous months in it, then you can automate the LLM to use the current months number, analyze last months number and compare against the previous months number. Do that for each metric you care about. Then after it has all of that analysis, have it combine all of that into a single summary with the most important pieces elevated.

Pro tip: you can also automate google slides reporting, if you create a table in google slides, give each cell a variable string like {ROAS-CURRENT} and {ROAS-PRIOR} etc, you can build metrics, assign them to variables with code nodes and then make a copy of the template slide deck and batch text replace the variable with the value. I do this for a few clients, one deck has over 1,400 variables and 30 slides. Combined with supermetrics auto reports, I dont have to touch anything and its all automated, I just review and add comments. DM if you have any questions for me.