Agent Doctor

Agent /doctor Health Check

Validates every external dependency, API credential, MCP server, and tool the current agent relies on. Catches failures before the user hits them.

Trigger

Use when the user says "/doctor", "health check", "check my connections", "is everything working", "diagnose my setup", "why isn't X working", "validate my environment", or at the start of a session when reliability matters.

Phase 1: Discover Dependencies

Scan the current environment to build a dependency manifest:

1. API Credentials

Check ~/.env.shared (and any local .env) for known API key patterns:

For each found key: verify it's non-empty and not a placeholder.

2. MCP Servers

Check Claude Code's MCP configuration for registered servers. For each:

• Is the server process running?
• Can we list tools from it?

3. SSH Connections

Check configured SSH hosts from ~/.ssh/config. Read the host list from the config rather than assuming; a typical set looks like:

• a workstation host (may be Windows -- use cmd.exe syntax, not Linux)
• a NAS or file server
• a tablet or laptop that may be asleep

For each: attempt a quick connection test (ssh <host> echo ok or equivalent).

4. External Services

Check reachability of known service URLs:

• the container manager: https://<host>:19943
• n8n: http://<host>:5678
• Any project-specific endpoints

5. Local Tools

Verify key CLI tools are installed and accessible:

• git, gh (GitHub CLI)
• node, npm
• python3, pip
• rclone (Google Drive)
• yt-dlp (YouTube)
• ffmpeg
• sqlite3

Phase 2: Run Health Checks

For each dependency, run a lightweight validation:

API Keys -- make a minimal API call (list models, get profile, etc.) to confirm auth works. Do NOT make billable calls -- use free/info endpoints only.

SSH Hosts -- ssh -o ConnectTimeout=5 <host> echo ok 2>&1. Interpret: success, timeout (host off), refused (host up but SSH down), or key failure.

HTTP Services -- curl -sk -o /dev/null -w '%{http_code}' <url>. Interpret: 200/302 = healthy, 401 = auth issue, timeout = unreachable.

CLI Tools -- which <tool> && <tool> --version 2>&1 | head -1. Interpret: found + version = healthy, not found = missing.

MCP Servers -- check if server process is running and responsive.

Phase 3: Report

Output a single compact diagnostic:

Agent Health Check
==================
Date: YYYY-MM-DD HH:MM

API Credentials
  Anthropic       [OK] claude-sonnet-4-20250514 accessible
  Google/Gemini   [OK] key valid
  GitHub          [OK] authenticated as <user>
  the container manager       [OK] token acquired
  OpenRouter      [WARN] key present but untested
  Firecrawl       [FAIL] key empty or missing

SSH Connections
  workstation     [OK] Windows cmd.exe responding
  nas             [OK] BusyBox Linux responding
  tablet          [FAIL] timeout -- likely asleep

HTTP Services
  the container manager API   [OK] https://<host>:19943 (200)
  n8n             [OK] http://<host>:5678 (200)

MCP Servers
  google-calendar [OK] 5 tools registered
  Gmail           [OK] 8 tools registered
  Notion          [OK] 12 tools registered
  context-store   [WARN] server not running

CLI Tools
  git 2.43.0      [OK]
  gh 2.45.0       [OK]
  node 20.11.0    [OK]
  python3 3.12.3  [OK]
  rclone 1.65.0   [OK]
  ffmpeg          [FAIL] not installed

Summary: 15/18 healthy | 2 warnings | 1 failure

Phase 4: Remediation Suggestions

For each FAIL or WARN, provide a one-line fix:

Fixes needed:
  - Firecrawl: Add FIRECRAWL_API_KEY to ~/.env.shared
  - surface: Machine likely asleep -- wake via network or ignore
  - ffmpeg: sudo apt install ffmpeg

Phase 5: Store Results (Optional)

If the user wants to track health over time:

echo "$(date -I),$(echo $RESULT_SUMMARY)" >> ~/.claude/doctor-log.csv

Scope Control

This skill checks what's available in the current environment. It does NOT:

• Make paid API calls to verify credits/billing
• Modify any configuration
• Install missing dependencies (only suggests how)
• Store credentials or tokens

Source Attribution

Technique derived from Nate's Newsletter (2026-04-03): "Your Agent Is 80% Plumbing" -- the /doctor health check as one of 12 core infrastructure primitives, validating API credentials, external connections, config integrity, tool availability, and resource health at startup and on demand.