**Spec-driven development fails because specs become outdated and mislead both humans and coding agents.** The solution: a self-updating spec that both developers and agents read from AND write to, keeping it accurate as the implementation evolves. Agents should update the plan when they discover new information, just like a good junior engineer would. ## Core Insight Augment Code identifies the critical flaw in specification-driven development: specs are treated as static documents handed down to implementers. But implementation always reveals information the spec didn't anticipate. Static specs become lies that mislead agents into wrong assumptions. The fix: make the spec a living, bidirectional document. Agents read it for direction AND write back what they learned during implementation. This keeps the spec truthful and useful throughout the project lifecycle. ## Key Principles - **Specs decay**: Any spec that isn't updated during implementation becomes a misleading artifact - **Bidirectional flow**: Agents must write TO specs, not just read FROM them - **Junior engineer analogy**: Good engineers update task descriptions when they discover new information; agents should too - **Truth maintenance**: A spec's value is proportional to its accuracy, which requires continuous updating ## Cross-Domain Connections - Extends [[Specification-Driven Development as Multi-Agent Coordination Mechanism]] — specs as coordination, but THIS adds the crucial "living document" requirement - Connects to [[Agent Identity Framework as Values Driven Autonomy Pattern]] — agents with values naturally update shared context - Supports [[Deliberate Deceleration in AI-Assisted Dev]] — updating specs IS the deliberate review loop - Relates to Agile methodology — living specs mirror the iterative, feedback-driven approach ## Source - [[What spec-driven development gets wrong]] (Augment Code tweet, February 2026): https://x.com/augmentcode/status/2025993446633492725 --- *Atomic concept extracted: 2026-02-24* *Topic: AI-Assisted Development*