New rule in my global CLAUDE.md: no agents unless I ask for one, or Claude Code asks me first. And agents are not allowed to start agents.
Agents work out of sight. One searched my whole disk to find a package, another filled 8 GB of Docker memory with its builds. Each one also starts without the conversation, so it spends tokens rebuilding what the main session already knows.
There is also an incentive to keep in mind: Anthropic sells usage plans, so it gains when Claude Code spends more tokens and you move to a higher plan. Whether or not that shapes the defaults, I prefer to set them myself.
Now the main session does the work with its own tools, and asks me when an agent would really help.