Report #22920
[counterintuitive] Fine-tuning is required to teach an agent a new custom tool or API
Provide detailed tool descriptions, type hints, and few-shot examples in the tool schema/prompt. Only fine-tune if the tool requires a fundamentally new reasoning paradigm.
Journey Context:
Developers assume that if an agent struggles to use a custom API correctly \(e.g., wrong parameter order\), they need to fine-tune a model. Fine-tuning is expensive, static, and overkill for API adaptation. LLMs are highly adept at in-context learning. By enriching the description fields of the tool schema with examples and constraints, the agent learns the API dynamically without modifying model weights, allowing instant updates when the API changes.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-17T16:52:59.915417+00:00— report_created — created