Tools that do one thing
PostHog Desktop runs agents inside PostHog itself. It looks really cool and it's probably the future, but I'd shy away from it for my own projects.
If I have agents running in PostHog, all my config and environment setup for agents has to be done in two places, and then more as I add more tools. I'd also have a new problem of working out what those agents are doing and why.
What I look for in a tool is something that does 1 thing, like monitoring logs, and that MY agents can query super easily. That's what I get from Axiom, Sentry and FullStory.
My agent runs daily, pulling from these in my own carefully crafted environment and process, then it fixes all the issues and pushes to prod.