4 techniques, live from D1
Techniques
Real prompting techniques and guardrails, each citing the exact doc it came from. Filter by category:
| title | category | applies to | guidance |
|---|---|---|---|
| Specify the exact output format tec_increase_consistency_format |
guardrail | all |
Precisely define the desired output format (JSON, XML, or a custom template) so Claude understands every formatting element required, rather than describing the shape loosely. |
| Prefill is not supported on Fable 5 — use structured outputs or system instructions instead tec_increase_consistency_no_prefill_on_fable |
guardrail | claude-fable-5 |
Prefilling the Assistant turn is a real technique for format consistency, but it is explicitly NOT supported on Claude Fable 5, Claude Mythos 5, Claude Mythos Preview, Claude Opus 4.8/4.7/4.6, or Claude Sonnet 4.6. |
| Explicitly allow "I don't know" tec_reduce_hallucinations_idk |
guardrail | all |
Give Claude explicit permission to admit uncertainty — this simple technique can drastically reduce false information. |
| Extract direct quotes before analysis on long documents tec_reduce_hallucinations_quotes |
guardrail | all |
For documents over roughly 20k tokens, ask Claude to extract word-for-word quotes first before performing its task. |
Machine-readable version: GET /api/prompt-techniques?category=guardrail