docs: narrow coding standards scope

.agents/skills/coding-standards/SKILL.md

@@ -1,12 +1,18 @@
 ---
 name: coding-standards
-description: Universal coding standards, best practices, and patterns for TypeScript, JavaScript, React, and Node.js development.
+description: Baseline cross-project coding conventions for naming, readability, immutability, and code-quality review. Use detailed frontend or backend skills for framework-specific patterns.
 origin: ECC
 ---
 
 # Coding Standards & Best Practices
 
-Universal coding standards applicable across all projects.
+Baseline coding conventions applicable across projects.
+
+This skill is the shared floor, not the detailed framework playbook.
+
+- Use `frontend-patterns` for React, state, forms, rendering, and UI architecture.
+- Use `backend-patterns` or `api-design` for repository/service layers, endpoint design, validation, and server-specific concerns.
+- Use `rules/common/coding-style.md` when you need the shortest reusable rule layer instead of a full skill walkthrough.
 
 ## When to Activate
 
@@ -17,6 +23,19 @@ Universal coding standards applicable across all projects.
 - Setting up linting, formatting, or type-checking rules
 - Onboarding new contributors to coding conventions
 
+## Scope Boundaries
+
+Activate this skill for:
+- descriptive naming
+- immutability defaults
+- readability, KISS, DRY, and YAGNI enforcement
+- error-handling expectations and code-smell review
+
+Do not use this skill as the primary source for:
+- React composition, hooks, or rendering patterns
+- backend architecture, API design, or database layering
+- domain-specific framework guidance when a narrower ECC skill already exists
+
 ## Code Quality Principles
 
 ### 1. Readability First