---
phase: 4
slug: custom-tool-mcp-proxy
status: validated
nyquist_compliant: true
wave_0_complete: true
created: 2026-03-14
---

# Phase 4 — Validation Strategy

> Per-phase validation contract for feedback sampling during execution.

---

## Test Infrastructure

| Property | Value |
|----------|-------|
| **Framework** | vitest ^3.0.0 |
| **Config file** | vitest.config.ts |
| **Quick run command** | `npx vitest run --reporter=verbose` |
| **Full suite command** | `npx vitest run --reporter=verbose` |
| **Estimated runtime** | ~3 seconds |

---

## Sampling Rate

- **After every task commit:** Run `npx vitest run --reporter=verbose`
- **After every plan wave:** Run `npx vitest run --reporter=verbose`
- **Before `/gsd:verify-work`:** Full suite must be green
- **Max feedback latency:** 3 seconds

---

## Per-Task Verification Map

| Req ID | Requirement | Test Type | Automated Command | File Exists | Status |
|--------|-------------|-----------|-------------------|-------------|--------|
| MCP-01 | Custom tools discovered and filtered from built-ins | unit | `npx vitest run tests/mcp-config.test.ts -t "getCustomToolDefs"` | ✅ | ✅ green |
| MCP-01 | MCP config written with correct server entry | unit | `npx vitest run tests/mcp-config.test.ts -t "writeMcpConfig"` | ✅ | ✅ green |
| MCP-01 | --mcp-config flag passed to subprocess | unit | `npx vitest run tests/process-manager.test.ts -t "mcp-config"` | ✅ | ✅ green |
| MCP-02 | mcp__custom-tools__ prefix stripped from tool names | unit | `npx vitest run tests/tool-mapping.test.ts -t "MCP prefix stripping"` | ✅ | ✅ green |
| MCP-02 | isCustomToolName identifies non-built-in tools | unit | `npx vitest run tests/tool-mapping.test.ts -t "isCustomToolName"` | ✅ | ✅ green |
| CONF-01 | No --strict-mcp-config flag (user configs load automatically) | unit | `npx vitest run tests/process-manager.test.ts -t "strict-mcp-config"` | ✅ | ✅ green |

*Status: ⬜ pending · ✅ green · ❌ red · ⚠️ flaky*

---

## Wave 0 Requirements

- [x] `tests/mcp-config.test.ts` — MCP-01 (custom tool discovery, config generation)
- [x] MCP prefix stripping tests in `tests/tool-mapping.test.ts` — MCP-02
- [x] --mcp-config and --strict-mcp-config tests in `tests/process-manager.test.ts` — MCP-01, CONF-01

*Note: Original VALIDATION.md listed `tests/mcp-server.test.ts` — the MCP server (`mcp-schema-server.cjs`) is tested indirectly through mcp-config.test.ts (config generation) and provider integration.*

---

## Manual-Only Verifications

| Behavior | Requirement | Why Manual | Test Instructions |
|----------|-------------|------------|-------------------|
| Custom tools appear in Claude's tool list | MCP-01 | Requires live Claude CLI subprocess with MCP server | Run extension with a custom tool registered, verify Claude proposes calling it |
| User `.mcp.json` configs load alongside custom-tools | CONF-01 | Requires real Claude CLI with existing MCP configs | Run extension in a project with `.mcp.json`, verify both servers are active |

---

## Validation Sign-Off

- [x] All tasks have automated verify or Wave 0 dependencies
- [x] Sampling continuity: no 3 consecutive tasks without automated verify
- [x] Wave 0 covers all MISSING references
- [x] No watch-mode flags
- [x] Feedback latency < 3s
- [x] `nyquist_compliant: true` set in frontmatter

**Approval:** approved 2026-03-15

## Validation Audit 2026-03-15
| Metric | Count |
|--------|-------|
| Gaps found | 0 |
| Resolved | 0 |
| Escalated | 0 |