Add embedded CLI example (#352)

Add example for MCP servers embedded inside a CLI tool and update
example validator count.

## Motivation and Context
Document how to model CLI-embedded MCP servers using existing
packages/arguments, per discussion
[#274](https://github.com/modelcontextprotocol/registry/discussions/274).
No schema changes.

## How Has This Been Tested?
- Ran validators: schemas valid; 11/11 examples pass.
- Scripts: ./tools/validate-schemas.sh, ./tools/validate-examples.sh

## Breaking Changes
None.

## Types of changes
- [ ] Bug fix (non-breaking change which fixes an issue)
- [ ] New feature (non-breaking change which adds functionality)
- [ ] Breaking change (fix or feature that would cause existing
functionality to change)
- [x] Documentation update

## Checklist
- [x] I have read the [MCP
Documentation](https://modelcontextprotocol.io)
- [x] My code follows the repository's style guidelines
- [x] New and existing tests pass locally
- [ ] I have added appropriate error handling
- [x] I have added or updated documentation as needed

## Additional context
Startup reference: [Agentic integrations - Snyk MCP
Server](https://docs.snyk.io/integrations/developer-guardrails-for-agentic-workflows)

---------

Co-authored-by: Adam Jones <adamj@anthropic.com>
Co-authored-by: adam jones <adamj+git@anthropic.com>

docs/server-json/examples.md

@@ -621,6 +621,43 @@ This example shows an MCPB (MCP Bundle) package that:
 - Includes a SHA-256 hash for integrity verification
 - Can be downloaded and executed directly by MCP clients that support MCPB
 
+## Embedded MCP inside a CLI tool
+
+Some CLI tools bundle an MCP server, without a standalone MCP package or a public repository. In these cases, reuse the existing `packages` shape by pointing at the host CLI package and supplying the `package_arguments` and `runtime_hint` if needed to start the MCP server.
+
+```json
+{
+  "$schema": "https://static.modelcontextprotocol.io/schemas/2025-07-09/server.schema.json",
+  "name": "io.snyk/cli-mcp",
+  "description": "MCP server provided by the Snyk CLI",
+  "status": "active",
+  "version_detail": {
+    "version": "1.1298.0"
+  },
+  "packages": [
+    {
+      "registry_type": "npm",
+      "registry_base_url": "https://registry.npmjs.org",
+      "identifier": "snyk",
+      "version": "1.1298.0",
+      "transport": {
+        "type": "stdio"
+      },
+      "package_arguments": [
+        { "type": "positional", "value": "mcp" },
+        {
+          "type": "named",
+          "name": "-t",
+          "description": "Transport type for MCP server",
+          "default": "stdio",
+          "choices": ["stdio", "sse"]
+        }
+      ]
+    }
+  ]
+}
+```
+
 ## Deprecated Server Example
 
 ```json

tools/validate-examples/main.go

@@ -24,7 +24,7 @@ const (
 	// IMPORTANT: Only change this count if you have intentionally added or removed examples
 	// from the examples.md file. This check prevents accidental formatting changes from
 	// causing examples to be skipped during validation.
-	expectedExampleCount = 11
+	expectedExampleCount = 12
 )
 
 func main() {