Document agent skills guidance

Author: linhay

AGENTS.md

@@ -65,6 +65,10 @@ swift test --package-path . --filter <TestName>
   - No Copilot instructions file found at `.github/copilot-instructions.md`.
   - If you add Cursor/Copilot rules, place them in `.cursor/rules/` and reference them here.
 
+- **Skills**
+  - If your agent supports skills, follow the `SKILL.md` instructions for any skill you use.
+  - This repo does not define repo-specific skills; rely on your toolchain's skill list when available.
+
 - **Code style guidelines**
 
 - Imports

README.md

@@ -118,6 +118,7 @@ CI
 
 Contributing and agents
 - There is an `AGENTS.md` file with rules and commands for automated agents and contributors. Agents should follow its guidelines when editing, testing, and committing.
+- Skill guidance for agent-enabled environments is also noted in `AGENTS.md`.
 
 Example usage
 - Simple programmatic example (conceptual):