Pure-LLM lockdown mode with --tools ""

Tell claude it has zero built-in tools. The pipe data is the only context. Bulletproof for production cron jobs — claude literally cannot touch your filesystem.

$ curl -s "https://hn.algolia.com/api/v1/search?tags=front_page&hitsPerPage=20" \
  | jq -r '.hits[] | "- \(.title)"' \
  | claude -p \
      --tools "" \
      --no-session-persistence \
      "Extract the 3 titles most relevant to AI inference cost. Output as a markdown list. No other prose."

1. [01] curlcurl … hn.algolia.com/api/v1/search?tags=front_page …
   HN's current front page via Algolia.
2. [02] jqjq -r '.hits[] | "- \(.title)"'
   Markdown bullet list of titles — tight prompt input.
3. [03] claude--tools ""
   Empty string disables ALL built-in tools (Bash, Read, Edit, Grep, ...). Claude is reduced to pure LLM with stdin as its only context. Perfect for production: even if a malicious prompt tells claude to `rm -rf /`, claude has no tool to do it.
4. [04] claude--no-session-persistence
   Don't write the session to disk. Required for cron — no on-disk traces, no growing session files.

- The hidden cost of LLM batching
- Apple Silicon M5 Pro benchmarks
- A vector DB in 200 lines of Rust

• `--tools ""` disables built-in tools only — MCP tools loaded via --mcp-config remain available. Combine with `--strict-mcp-config` for full lockdown.
• For scoped tool access: `--tools "Read,Grep,Glob"` (read-only) or `--allowedTools "Bash(git log:*)"` (per-pattern allowlist).