The usage-tracker skill enables developers to track and analyze tool or resource usage over time through timestamped logging and reporting. It's designed for generating periodic usage reports, monitoring quotas, and detecting usage trends, but is not suitable for real-time or high-frequency event tracking. Key capabilities include daily/weekly/monthly breakdowns and pattern analysis for building dashboards.

This skill enables parallel task execution in bash using xargs and job control for significant performance gains. It's ideal for batch operations on independent items like multiple files or repositories, particularly for I/O-bound tasks. Developers should use it when order doesn't matter and avoid it for tasks with dependencies or shared resource requirements.

This skill implements the XDG Base Directory Standard for managing application state, providing cross-platform directory paths for configuration, data, cache, and state files. It automatically handles environment variable fallbacks and creates application-specific subdirectories. Use this when building CLI tools or applications that need standardized, organized file storage across different operating systems.

This skill enables environment variable overrides for JSON configuration loading, allowing developers to prioritize environment settings over file-based values. It provides a Bash implementation that loads configurations from files while supporting prefixed environment variables as higher-priority overrides. Use this when you need flexible configuration management where environment-specific settings should supersede default file configurations.