mcp-probe

One command to diagnose your MCP server.

Tests every tool, resource, and prompt your server exposes — then gives you a health report with a pass/fail scorecard.

Built on the Anthropic Model Context Protocol (MCP) spec.

Note: Published to npm as @incultnitollc/mcp-probe. The CLI binary is mcp-probe. The unscoped name mcp-doctor on npm is owned by an unrelated tool, so this project ships under a scope. Versions <= 0.2.1 shipped under the deprecated @incultnitostudiosllc scope — install @incultnitollc/mcp-probe instead.

mcp-probe demo

npx @incultnitollc/mcp-probe test "npx -y @modelcontextprotocol/server-everything"

Test your MCP server in 30 seconds

Check	Description
Tool calling	Calls every tool with auto-generated sample arguments based on the input schema
Resource reading	Reads every resource and verifies content is returned
Prompt rendering	Gets every prompt with sample arguments and verifies messages are returned
Schema validation	Checks tool schemas for missing descriptions, broken required fields, malformed types
Health scoring	Summarizes everything into a pass/fail scorecard

Install

npm install -g @incultnitollc/mcp-probe

Or run directly:

npx @incultnitollc/mcp-probe test "your-server-command"

Usage

Local stdio server

npx @incultnitollc/mcp-probe test "npx -y @modelcontextprotocol/server-everything"

Remote server (Streamable HTTP)

npx @incultnitollc/mcp-probe test https://your-server.example.com/mcp

Remote server (SSE)

npx @incultnitollc/mcp-probe test https://your-server.example.com/mcp --transport sse

Authenticated remote server

npx @incultnitollc/mcp-probe test https://your-server.example.com/mcp \
  --header "Authorization: Bearer $TOKEN"

Options

Flag	Description
`--json`	Output results as JSON
`--timeout <ms>`	Per-operation timeout (default 30000)
`--transport <kind>`	Force `stdio`, `sse`, or `http` (auto-detected from target)
`--header <Name: value>`	Add header to remote transport. Repeatable.

Exit codes

0 — All checks passed
1 — One or more checks failed (useful for CI gates)

JSON output

Use --json to get structured output for automation:

mcp-probe test --json "your-server" | jq '.score'

{
  "toolsCallable": 12,
  "toolsTotal": 13,
  "resourcesReadable": 7,
  "resourcesTotal": 7,
  "promptsGettable": 3,
  "promptsTotal": 4,
  "schemaErrors": 0,
  "schemaWarnings": 1
}

How tool calling works

mcp-probe auto-generates arguments for each tool based on its inputSchema:

Only required fields get values (safest approach)
Uses default values and enum first choices when available
Infers smart defaults from field names (url → https://example.com, email → test@example.com)
Falls back to type-appropriate defaults (string → "test", number → 1, boolean → false)

This means tools with complex required inputs may fail — and that's useful information. It tells you your tool isn't self-contained enough for automated testing.

Use cases

MCP server development — Run mcp-probe in your test suite to catch regressions
CI/CD gates — Block deploys if your MCP server doesn't pass health checks
Server evaluation — Quickly assess third-party MCP servers before integrating them
Schema quality — Find missing descriptions and malformed schemas before users hit them

CI integration

mcp-probe exits 0 on full pass and 1 on any failure, so it drops directly into any CI pipeline:

# .github/workflows/mcp-health.yml
- name: Health-check MCP server
  run: npx @incultnitollc/mcp-probe test "$MCP_SERVER_CMD"

Use --json for structured output and jq to gate on specific metrics (e.g. fail the build if schemaWarnings > 0). A dedicated GitHub Action is on the roadmap.

Compared to MCP Inspector

The official MCP Inspector is a GUI for interactive exploration — point, click, see what a server returns. mcp-probe is a CLI for automated, repeatable diagnosis — every tool/resource/prompt called automatically, pass/fail scorecard out, exit code in. Use Inspector when you're exploring; use mcp-probe in CI, in pre-publish checks, or when you want a shareable scorecard of someone else's server.

Development

git clone https://github.com/incultnitollc/mcp-probe.git
cd mcp-probe
npm install
npm run dev -- test "npx -y @modelcontextprotocol/server-everything"
npm test

License

MIT - Incultnito LLC

@incultnitollc/mcp-probe

Quick Install