Lists multiple specific concrete patterns and actions: functional options, constructors, error flow and cascading, resource management and lifecycle, graceful shutdown, resilience, architecture, dependency injection, data handling, and streaming. These are concrete, recognizable Go design concepts.

Clearly answers both 'what' (idiomatic Golang design patterns covering functional options, constructors, error flow, etc.) and 'when' ('Apply when designing Go APIs, structuring applications, choosing between patterns, making design decisions, architectural choices, or production hardening'). The explicit 'Apply when...' clause satisfies the trigger guidance requirement.

Includes strong natural keywords users would say: 'Golang', 'Go APIs', 'functional options', 'graceful shutdown', 'dependency injection', 'error flow', 'design patterns', 'production hardening', 'architectural choices'. These cover a wide range of terms a Go developer would naturally use.

Clearly scoped to Go/Golang design patterns specifically, with distinct triggers like 'Go APIs', 'Golang', 'functional options', and 'graceful shutdown'. Unlikely to conflict with general coding skills or skills for other languages due to the language-specific and pattern-specific terminology.

Generally efficient with good use of tables and code examples, but some explanations are unnecessary for Claude (e.g., explaining why init() is bad, explaining what defer does). The best practices summary is dense and useful, but some inline commentary like 'they scale better as APIs evolve' and 'later code changes can accidentally skip cleanup' explain things Claude already knows.

Provides fully executable, copy-paste ready Go code examples for functional options, regexp compilation, embed directives, resource management, and timeout patterns. The code is complete and idiomatic, not pseudocode.

This is a pattern reference rather than a multi-step workflow, so strict sequencing is less critical. However, the two operational modes (Design mode and Review mode) are described but lack concrete validation steps — Review mode says 'scan for issues, report findings before suggesting refactors' but doesn't provide a checklist or explicit sequence for the review process.

Excellent progressive disclosure with a clear overview in the main file and well-signaled one-level-deep references to both internal files (references/data-handling.md, references/resource-management.md, references/architecture.md, etc.) and cross-referenced skills. The detailed guides table is particularly well-organized for navigation.