When to Use Agent Mode vs. Chat

Modern AI coding tools have two modes:

• Chat: ask a question, get an answer. The tool does not act on your behalf.
• Agent mode: the tool reads files, runs commands, edits code, and loops until a goal is reached.

Agent mode is more powerful but also more expensive, slower, and harder to control. Use it deliberately.

Use chat for

• Explaining a function or file
• Drafting a snippet in isolation
• Brainstorming approaches
• Quick questions that do not need project context

Use agent mode for

• Multi-file refactors
• Adding a feature that touches tests, docs, and config
• Debugging that requires running commands and reading logs
• Repetitive tasks you have already done manually once

Cost and speed

Agent mode usually sends many more tokens than chat because it includes file context, tool results, and loop history. A single agent session can cost 10–50x more than a chat exchange.

Mode	Tokens	Latency	Control
Chat	Low	Seconds	High
Agent mode	High	Minutes	Lower

How to keep agent mode safe

1. Start with a narrow goal. "Add input validation to the signup form" is better than "fix the app."
2. Review every diff before applying.
3. Disable auto-approval for shell commands and file writes.
4. Run tests and linters after the agent finishes.
5. Keep a git checkpoint so you can revert.

Verdict

Default to chat. Escalate to agent mode only when the task genuinely spans multiple files or requires iteration. Your tokens and your sanity will last longer.