Summary

Lean Build is a code architecture and feature development skill that guides agents to construct minimal, end-to-end feature slices within a system. It emphasizes architecture-first design, layer-aware tracing, and explicit scope constraints to avoid overbuilding and unnecessary complexity.

Detected Capabilities

Trigger Keywords

Phrases that MCP clients use to match this skill to user intent.

Use Cases

• Implement new product features with strict scope boundaries
• Design feature work that respects architectural layers and invariants
• Build integrations that reuse existing system seams
• Deliver end-to-end feature paths across multiple layers
• Prevent scope creep and overbuilding in feature development

Quality Notes

• Instructions are architecture-focused and prescriptive but use highly abstract language that assumes domain knowledge about 'Native Core', 'layers', 'seams', and 'invariants'
• No concrete examples provided to illustrate the abstract principles (e.g., what does 'trace entry point through layers' look like in practice?)
• Scope is clear (feature development with focus on minimal viable work) but the execution guidance is vague and relies heavily on implicit system knowledge
• The skill lacks actionable decision trees or checklists — an agent must infer what constitutes 'acceptance', 'material tradeoff', or 'coherent end-to-end path'
• No documented limitations or edge cases (e.g., how to handle requests that span multiple architectural boundaries)
• The phrase 'Keep work runnable; preserve Core safety' is mentioned but not defined — unclear what constitutes a safety violation
• No supporting context on how to identify 'fitting seams' or when refactoring is justified
• Strong architectural vision but insufficient scaffolding for agents unfamiliar with the specific system's design principles