Claude Code Skill Tax: 2,596 Installed Skills, 40 Used, $91/Month Wasted

If you use Claude Code with multiple skill marketplaces, there's an invisible tax on every session: all installed skills are loaded into the system prompt, whether you use them or not. User chataxis measured the impact and open-sourced a tool to surface the data.

The Problem

Every skill you install gets injected into the system prompt of every session. The harness needs to "see" them to know they exist. In one real installation:

• 2,596 skills installed across 3 marketplaces
• 102,651 tokens loaded into every session
• 40 skills ever invoked
• 98.6% never used — pure tax

Cost estimate at typical usage: ~$91/month. 96% of that cost came from a single marketplace. No warning, no billing line, no progress bar.

Open-Source Auditing Tool: skill-tax

The skill-tax repo provides three commands. It never deletes anything — just shows you the data.

• audit: what each skill costs you per session (token count)
• usage: what you've actually invoked, mined from local transcripts (no hooks, no waiting)
• report: combined view, ranked cleanup candidates

Who This Is For

Claude Code users who install skills from multiple marketplaces and want to reduce wasted tokens and costs.