I found $2,500/year of hidden token waste in my Claude Code setup. It was the MCP servers.
Last week I noticed my Claude Code conversations were dying at around message 15. Context window full. The model starts forgetting earlier instructions. Tool calls fail. The conversation degrades into hallucination.
I assumed it was my fault โ too many messages, too much context. So I started measuring.
Here's what I found:
Session start:
Claude system prompt: ~8,000 tokens
MCP schema injection: ~111,000 tokens
User's first message: 50 tokens
โโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโ
Total before any work: ~119,000 tokens
Remaining context: ~81,000 tokens
I was starting every conversation with 60% of my context already consumed.
The culprit wasn't my prompts. It was the 10 MCP servers I had proudly configured in my claude_desktop_config.json
.
I measured each server's schema injection using tiktoken:
| Server | Why I Installed It | Token Cost | Times Used/Week |
|---|---|---|---|
| GitHub | PR reviews, issues | 12,440 | 3 |
| Slack | Message reading | 14,672 | 0 |
| Google Drive | Doc access | 47,293 | 1 |
| Notion | Knowledge base | 13,780 | 2 |
| Postgres | Query DB | 8,231 | 4 |
| Puppeteer | Screenshots | 5,890 | 0 |
| Filesystem | File access | 3,847 | 15 |
| Brave Search | Web search | 2,103 | 5 |
| Memory | Context persistence | 2,567 | 0 |
| Sequential Thinking | Reasoning | 890 | 2 |
| Total | |||
| 111,713 |
Look at the "Times Used/Week" column. Three servers were used zero times. Two more were used once or twice. But every single one of them was injecting 100% of its schema into every conversation.
I was paying $0.33 per conversation โ $2,500/year โ to load schemas for tools I barely used.
I posted my findings on Bluesky. Within hours:
"I had the same issue. Removed 6 MCP servers and my conversations went from dying at message 15 to lasting 40+ messages." โ
[@developer1]"GitHub MCP is 12K tokens but Claude Code already has
gh
CLI built in. Why did I install it?" โ @developer2"Google Drive MCP alone is 47K tokens. FORTY SEVEN THOUSAND. For a tool I used once this month." โ @developer3
This isn't a niche problem. Everyone running 5+ MCP servers is silently burning 50-100K tokens per conversation.
pip install mcptoon
mcptoon audit --config ~/.config/claude/claude_desktop_config.json
Output:
Filesystem: 3,847 tokens โ Keep (used daily)
GitHub: 12,440 tokens โ Remove (use `gh` CLI instead)
Google Drive: 47,293 tokens โ Remove (use `gdrive` CLI)
Slack: 14,672 tokens โ Remove (use `slack` CLI)
Notion: 13,780 tokens โ Depends (no good CLI alternative)
Postgres: 8,231 tokens โ Keep (used 4x/week)
...
Total waste: 89,702 tokens โ $1,346/year
{
"mcpServers": {
"filesystem": { ... },
"postgres": { ... },
"brave-search": { ... }
}
}
I went from 10 servers to 3. My context overhead dropped from 111K to 14K tokens.
For servers you must keep, wrap them with mcptoon to compress schemas:
{
"mcpServers": {
"postgres": {
"command": "mcptoon",
"args": ["serve", "--stdio", "npx", "@modelcontextprotocol/server-postgres"]
}
}
}
mcptoon compresses tool schemas by 97% using a compact TOON format. The model sees the same tools but with 3K tokens instead of 111K.
| Metric | Before | After | Change |
|---|---|---|---|
| Context at session start | 111K tokens | 3.2K tokens | -97% |
| Conversations before context death | ~15 messages | ~45 messages | 3x |
| Token cost per conversation | $0.54 | $0.14 | -74% |
| Monthly cost (20 conv/day ร 22 days) | $237 | $62 | -$175 |
| Annual savings | โ | โ | $2,100 |
This isn't just about money. The real cost of MCP schema bloat is cognitive degradation:
When Perplexity's CTO announced they were replacing MCP with REST API + CLI internally, this is what he was talking about. When Garry Tan said "MCP sucks honestly," this is what he meant. When Anthropic's own engineers showed 98.7% token reduction by not schemas into context, this is the problem they were solving.
MCP servers aren't bad. The protocol isn't bad. But ** every tool schema into context at startup is a design flaw that costs every developer thousands of dollars per year in wasted tokens.**
Most developers don't know this because:
Now you know. Go audit your config.
pip install mcptoon
mcptoon audit --config your-config.json
mcptoon is open source, Apache 2.0, 250KB, zero dependencies. GitHub ยท PyPI. All measurements use tiktoken cl100k_base. Not affiliated with Anthropic.