Don't Use a Chat Model for Reasoning Tasks

General-purpose chat models (GPT-4o, Claude's standard models) are optimized for fluent, fast conversation. Dedicated reasoning models are optimized for multi-step logic — parsing, math, code, structured decision trees.

Using a chat model for a genuinely logic-heavy task (parsing conditional business rules, multi-step calculations) often means paying more for a worse answer, because the model isn't built to reason step-by-step the way a reasoning-tuned model is.

The fix:

for anything that's really a logic/parsing problem — not a conversation — check whether your provider has a reasoning-specific model in their lineup, and test it against your actual use case before defaulting to the general chat model out of habit.