Matthew Weihl's language-agnostic preferences for straightforward, readable code. Use when reviewing code you did not write, when judging whether existing code meets these standards, or when the user asks about style, naming, function design, control flow, error handling, or structure.
Shared vocabulary for designing deep modules. Use when the user wants to design or improve a module's interface, find deepening opportunities, decide where a seam goes, make code more testable or AI-navigable, or when another skill needs the deep-module vocabulary.
Review a diff for correctness and maintainability. Use for strict checks on structure, abstractions, branching, module depth, and code style. Do not use for a style-only review or a whole-codebase architecture scan.