Guardrail for unexpected costs from CLI-invoked external paid tools (e.g. Gemini CLI)

While using Claude Code on a long-running project, I set up a workflow where Claude proactively invoked the gemini CLI as a "second opinion" collaborator, believing it was covered by my existing Gemini Pro subscription. It wasn't -- the gemini CLI bills real pay-per-token API usage, separate from consumer Pro/Advanced plans -- and I was billed $228 unexpectedly as a result.

Feature request: a standard setting/guardrail so Claude Code pauses and asks for explicit confirmation before invoking an external tool/CLI that incurs its own separate billing (beyond some configurable allotment), rather than relying entirely on the user or project docs to have gotten the cost model right up front. This would apply broadly to any project-configured external paid API/CLI a session might reach for repeatedly, not just Gemini specifically.