Skill 'writing-clearly-and-concisely' from superpowers plugin not discoverable as slash command

Description

The skill writing-clearly-and-concisely from the superpowers@claude-plugins-official plugin (v5.0.4) exists in the correct directory structure with valid SKILL.md frontmatter, but is not discoverable as a slash command (/writing-clearly-and-concisely or /superpowers:writing-clearly-and-concisely).

Environment

• Claude Code: VS Code extension
• Plugin: superpowers@claude-plugins-official v5.0.4
• OS: Windows 11 Pro
• Install path: C:\Users\honza\.claude\plugins\cache\claude-plugins-official\superpowers\5.0.4

Steps to reproduce

1. Install superpowers plugin (superpowers@claude-plugins-official)
2. Verify plugin is installed and enabled (shows in /plugin manager with green dot)
3. Verify skill exists: ~/.claude/plugins/cache/claude-plugins-official/superpowers/5.0.4/skills/writing-clearly-and-concisely/SKILL.md
4. Type /writing-clearly-and-concisely or /su in the chat input
5. Skill does not appear in autocomplete or available commands

Expected behavior

The skill should appear as an invocable slash command, similar to other superpowers skills like /simplify or /loop.

Actual behavior

• The skill is not listed in the system-reminder's available skills
• Typing /su shows no matches
• Other skills from the same plugin version DO work (e.g., simplify, loop)

Investigation

• installed_plugins.json confirms version 5.0.4 is active
• SKILL.md frontmatter is valid and identical in format to other working skills
• The skill was added in 5.0.4 (not present in 5.0.0 or 5.0.2)
• All other skills from 5.0.4 are discoverable

SKILL.md frontmatter

---
name: writing-clearly-and-concisely
description: Use when writing prose humans will read—documentation, commit messages, error messages, explanations, reports, or UI text. Applies Strunk's timeless rules for clearer, stronger, more professional writing.
---

This is identical in structure to other working skills (e.g., brainstorming, systematic-debugging).