What problem does it solve? Custom MSBuild targets often break silently: overwritten dependency chains drop SDK targets, query targets return stale results, and missing Inputs/Outputs cause unnecessary rebuilds. This Skill provides canonical patterns from Microsoft.Common.CurrentVersion.targets to author and review custom targets correctly. ## Core Features & Use Cases - Target Chain Patterns: Explains the Build→CoreBuild three-level pattern, DependsOnTargets vs BeforeTargets vs AfterTargets, and the $(XxxDependsOn) chain-extension convention. - Anti-Pattern Diagnosis: Detects broken SDK target chains (e.g., Directory.Build.targets redefining SDK targets), CompileDependsOn overwrites, and Returns vs Outputs misuse in query targets. - Complete Target Template: Provides a full custom target skeleton with validation targets, empty extensibility hooks, Inputs/Outputs incrementality, and FileWrites registration for clean tracking. - Use Case: A team's Directory.Build.targets silently replaces $(CompileDependsOn), dropping SDK code generation targets. Use this Skill to identify the overwrite and rewrite it as an append to the existing chain. ## Quick Start Review my custom MSBuild target in Directory.Build.targets and fix any chain-extension or incrementality anti-patterns.
