# Prompts Are Guidelines. Code Is the Config.

DevFeed: [Prompts Are Guidelines. Code Is the Config.](<https://devfeed.tech/articles/prompts-are-guidelines-code-is-the-config-30872.md>)

Original publisher: [Read original article](<https://brent.leekley.me/blog/prompt-vs-config/>)

Author: Brent Leekley

Published: 2026-06-08T00:00:00Z

Content type: tutorial

Language: en

Sources: [brent.leekley.me blog](<https://devfeed.tech/sources/brent-leekley-me-blog.md>)

Topics: [Artificial Intelligence](<https://devfeed.tech/topics/ai.md>), [Prompt Engineering](<https://devfeed.tech/topics/prompt-engineering.md>), [Claude](<https://devfeed.tech/topics/claude.md>), [API](<https://devfeed.tech/topics/api.md>), [hooks](<https://devfeed.tech/topics/hooks.md>), [JSON](<https://devfeed.tech/topics/json.md>), [context](<https://devfeed.tech/topics/context.md>)

Tags: [agent-reliability](<https://devfeed.tech/tags/agent-reliability.md>), [agents](<https://devfeed.tech/tags/agents.md>), [ai](<https://devfeed.tech/tags/ai.md>), [ai-agents](<https://devfeed.tech/tags/ai-agents.md>), [api](<https://devfeed.tech/tags/api.md>), [claude](<https://devfeed.tech/tags/claude.md>), [hooks](<https://devfeed.tech/tags/hooks.md>), [schema](<https://devfeed.tech/tags/schema.md>), [stateless](<https://devfeed.tech/tags/stateless.md>), [stop-reason](<https://devfeed.tech/tags/stop-reason.md>), [structured-output](<https://devfeed.tech/tags/structured-output.md>), [til](<https://devfeed.tech/tags/til.md>), [tool-use](<https://devfeed.tech/tags/tool-use.md>)

## AI overview

A Today I Learned field note about building more reliable AI agents by assigning probabilistic judgment to the model and deterministic guarantees to application code. It discusses using code-enforced gates and hooks for requirements that must always hold, branching on stop_reason rather than model text, handling turns that contain both chat and tool calls, and avoiding the assumption that a valid schema guarantees a correct answer.

## Source excerpt

Where the model's judgment ends and your code has to take over -- a Today I Learned field note on building AI agents that hold up in production: stop_reason, forced tool use, hooks, stateless history, and why a valid schema isn't a true answer.