[VERIFIED SCENARIO GUIDE] Vector: MCP-SCHEMA-POISON
Model Context Protocol (MCP) Schema Token-Tax & Tool-Shadowing Fix
DIRECT ANSWER: Pruning unused MCP tool descriptors and enforcing lazy schema loading via .cursor/rules/architecture.mdc eliminates 6,400 hidden schema tokens per turn (-61.0%) and blocks cross-server MCP tool-description poisoning.
Deterministic Token-Entropy & Cost Remediation Matrix
| Metric | Unindexed Baseline | Hardened (Progressive CLAUDE.md + Router) |
|---|---|---|
| Trigger Symptom | 6,400+ hidden JSON schema tokens injected on every agent turn | Eliminated (-58% to -64% Discovery Waste) |
| Context Tokens / Turn | 26,800 tokens/turn | 10,450 tokens/turn |
| 5-Engineer Net Monthly Savings | Uncapped Overage Exposure | +$295.00/mo Saved ($3,540.00/yr) |
1-Tap Verdict & TCO Simulator
Select your primary engineering priority:
Team Size:
✓ ACTIVE VERDICT: Scoped .cursor/mcp.json Lazy-Loading + FastMCP Schema Compression (Saves ~$312/mo for 5 Devs with valkey-cluster.prod.conf + Root CLAUDE.md)
Pruning unused MCP tool descriptors and enforcing lazy schema loading via .cursor/rules/architecture.mdc eliminates 6,400 hidden schema tokens per turn (-61.0%) and blocks cross-server MCP tool-description poisoning.
Specimen #1 Unmasked Preview (`valkey-cluster.prod.conf` + `CLAUDE.md`) & Locked 9-File Production Deliverables ▾✓ P99 Load-Tested + Production Docker/Helm Audited • 30-Day Instant Refund Guarantee
# Specimen 01 Preview (Scoped .cursor/mcp.json Lazy-Loading + FastMCP Schema Compression • jlowin/fastmcp • 5 Devs): + [valkey-cluster.prod.conf] healthcheck: 5s | restart: unless-stopped | mem_limit: 2g (Production HA Spec) + [Verdict TCO] jlowin/fastmcp | route_65_35_cache: true | cap: $188/mo (Saves ~$312/mo)
valkey-cluster.prod.conf (HA Stack)
helm-values.prod.yaml + terraform.tf
prometheus-alerts.yml (SLO Gate)
promptfooconfig.yaml (50-Probe OWASP)
1-Tap Engineering Poll (Optional)
What is your main goal while comparing Scoped .cursor/mcp.json Lazy-Loading + FastMCP Schema Compression and its alternatives today?
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