Template Validation skill: what it does and how to install it

What it does. Parses a template.json before semantic checks, then reports errors, warnings and suggestions for required fields, identity and short-name conflicts, symbols, source conditions, post-actions, constraints and tags. It produces a verdict and findings table with locations and concrete fixes, stopping at the parse error if JSON is malformed.

When to use it. Use it to review custom dotnet new templates before testing, packaging or publishing, or to diagnose missing templates and parameter behaviour. Do not use it to discover, instantiate or author templates.