Comment by everfrustrated

Worth pointing out that your IDE/plugin usually adds a whole bunch of prompts before yours - let alone the prompts that the model hosting provider prepends as well.

This might be what is encouraging the agent to do best practices like improvements. Looking at mine:

>You are a highly sophisticated automated coding agent with expert-level knowledge across many different programming languages and frameworks and software engineering tasks - this encompasses debugging issues, implementing new features, restructuring code, and providing code explanations, among other engineering activities.

I could imagine that an LLM could well interpret that to mean improve things as it goes. Models (like humans) don't respond well to things in the negative (don't think about pink monkeys - Now we're both thinking about them).