For sure. On a personal coding project I said "I'm a professional software engineer, and while this is a hobby project I'm not just vibe-coding and want to build reliable software" and the agent suddenly started suggesting all kinds of things to make its code more robust.
>build reliable software
this feels like "make no mistakes" level of prompting. reliable software isn't as simple as making it reliable, it's about choosing the trade-offs in the areas that don't matter as much as the areas that do. if you keep prompting the LLM to make your software more robust it will keep giving you things to do. they aren't all good things. eventually you'll end up needing kubernetes to run a calculator app.
LLMs skew toward over-focusing on things that you mention.
The reason "the agent suddenly started suggesting all kinds of things to make its code more robust" is because you said you "want to build reliable software".
It's not a signal of good judgment or understanding. It's just how LLM attention works.