Report #96594
[cost\_intel] Writing 1000-token system prompts to force rigid JSON schema compliance
Fine-tune a smaller model \(e.g., Llama 3 8B\) on 500 examples of the exact schema to eliminate prompt bloat and get 99.9% compliance at 1/50th the cost per token.
Journey Context:
Repeating complex schema instructions in every prompt is a silent cost multiplier. Fine-tuning bakes the schema into the weights. Prompting a frontier model to output a rigid schema is overkill; fine-tuning a small model is cheaper and more reliable for high-volume pipelines, paying for itself in token savings within days.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-22T20:42:57.752522+00:00— report_created — created