Cheatsheet 02 — Reading Model Cards & System Cards
What to extract, in what order, and the red flags. Full: Phase 3.
What a model card answers (read in this order)
- What is it? Base vs instruct/chat vs reasoning; size (params, active vs total for MoE); modality.
- Context window — max input+output tokens. (And max output separately — often smaller.)
- Training data & cutoff — knowledge cutoff date; domains; languages.
- Intended use & limits — what it's for, what it's not for.
- Capabilities — tool calling? structured output? reasoning? vision?
- Evaluations — which benchmarks, which numbers (and whether contaminated/self-reported).
- License & weights — open weights? commercial use? restrictions.
- Safety — refusals, red-team results, known failure modes (system cards go deep here).
Model card vs system card
| Model card | System card | |
|---|---|---|
| Focus | The model (architecture, evals, license) | The deployed system (safety, mitigations, policy) |
| Who writes | HF / labs (Google, Meta…) | Frontier labs (Anthropic, OpenAI) |
| Read for | Selection, capability, license | Safety posture, alignment pipeline, risk |
The numbers to write down (for selection)
- Context window (and max output).
- Price (input $/Mtok, output $/Mtok — output is usually pricier).
- Knowledge cutoff.
- Capabilities flags: tool calling, structured output, reasoning, vision.
- Open vs closed weights + license terms.
- Latency/throughput class (if stated).
Red flags 🚩
- Self-reported benchmarks only, no methodology → discount them; run your own eval.
- No knowledge cutoff stated → unknown staleness.
- Vague license ("research only", custom terms) → check commercial use (cheatsheet 05).
- Benchmark contamination not addressed → numbers may not transfer.
- Max output ≪ context window → can't generate long outputs even with big context.
- "State of the art" with no comparison baseline → marketing.
Interview line
"I never select on benchmark numbers alone — model cards shortlist; my own task eval + cost/latency decide. From a card I extract context, price, capabilities, cutoff, and license, then verify claims on my golden set." (Phase 5)
Next: 03 — models.dev Columns · Full: Phase 3