Caveman is a behavior pack. “Be concise” is a sentence.

“Be concise” can shorten one response. Caveman-style memory can change the default output pattern across a session. Neither fixes bloated input context by itself.

Use “be concise” for one-off control.

It is enough when you only need a shorter answer in the current conversation and do not care about cross-tool persistence.

Use a compact memory pack for repeated workflows.

When you switch between Claude Code, Codex, and Cursor, persistent memory rules prevent the same verbose behavior from returning in each tool.

Do not compress away safety.

For migrations, auth, payments, deletion, or production deployment, the right behavior is concise but explicit: keep risk notes, tests, and rollback details.