Add optional title field to server.json schema (#608)

## Summary

Introduces a new optional `title` field for MCP servers to provide a
clean, human-readable display name that clients and subregistries can
use for display purposes.

Fixes #606

## Changes

- Added `title` field to `ServerJSON` type (optional, max 100 chars)
- Added validation to reject titles ending with 'MCP Server', 'MCP
server', or 'MCP' suffixes
- Updated JSON schema and OpenAPI specification
- Added comprehensive test coverage for title validation
- Updated all documentation examples to demonstrate the new field

## Validation

The title field:
- Is optional (can be omitted)
- Must not be only whitespace if provided
- Must not end with MCP-related suffixes (case-insensitive)
- Can contain 'MCP' in the middle (e.g., "MCP Weather API" is valid)

Examples:
- ✅ Valid: "GitHub", "Weather API", "Slack Integration"
- ❌ Invalid: "GitHub MCP", "Weather MCP Server", "Slack-MCP"

---------

Co-authored-by: Claude <noreply@anthropic.com>

docs/reference/api/openapi.yaml

@@ -156,6 +156,7 @@ paths:
                 value:
                   name: "io.modelcontextprotocol/filesystem"
                   description: "Node.js server implementing Model Context Protocol (MCP) for filesystem operations."
+                  title: "Filesystem"
                   repository:
                     url: "https://github.com/modelcontextprotocol/servers"
                     source: "github"
@@ -177,6 +178,7 @@ paths:
                 value:
                   name: "com.example/demo-server"
                   description: "Example MCP server demonstrating publisher extensions."
+                  title: "Demo Server"
                   repository:
                     url: "https://github.com/example/mcp-demo"
                     source: "github"
@@ -267,7 +269,6 @@ components:
           description: "Optional relative path from repository root to the server location within a monorepo structure"
           example: "src/everything"
 
-
     ServerList:
       type: object
       required:
@@ -502,6 +503,10 @@ components:
           type: string
           description: "Human-readable description of the server's functionality"
           example: "Node.js server implementing Model Context Protocol (MCP) for filesystem operations."
+        title:
+          type: string
+          description: "Optional human-readable title or display name for the MCP server. MCP subregistries or clients MAY choose to use this for display purposes."
+          example: "Filesystem"
         repository:
           $ref: '#/components/schemas/Repository'
         version:

docs/reference/server-json/generic-server-json.md

@@ -25,6 +25,7 @@ The official registry has some more restrictions on top of this. See the [offici
   "$schema": "https://static.modelcontextprotocol.io/schemas/2025-09-29/server.schema.json",
   "name": "io.modelcontextprotocol.anonymous/brave-search",
   "description": "MCP server for Brave Search API integration",
+  "title": "Brave Search",
   "websiteUrl": "https://anonymous.modelcontextprotocol.io/examples",
   "repository": {
     "url": "https://github.com/modelcontextprotocol/servers",
@@ -71,6 +72,7 @@ For MCP servers located within a subdirectory of a larger repository (monorepo s
   "$schema": "https://static.modelcontextprotocol.io/schemas/2025-09-29/server.schema.json",
   "name": "io.modelcontextprotocol/everything",
   "description": "MCP server that exercises all the features of the MCP protocol",
+  "title": "Everything",
   "repository": {
     "url": "https://github.com/modelcontextprotocol/servers",
     "source": "github",
@@ -153,6 +155,7 @@ This will essentially instruct the MCP client to execute `dnx Knapcode.SampleMcp
   "$schema": "https://static.modelcontextprotocol.io/schemas/2025-09-29/server.schema.json",
   "name": "io.github.modelcontextprotocol/filesystem",
   "description": "Node.js server implementing Model Context Protocol (MCP) for filesystem operations.",
+  "title": "Filesystem",
   "repository": {
     "url": "https://github.com/modelcontextprotocol/servers",
     "source": "github",
@@ -288,6 +291,7 @@ This will essentially instruct the MCP client to execute `dnx Knapcode.SampleMcp
   "$schema": "https://static.modelcontextprotocol.io/schemas/2025-09-29/server.schema.json",
   "name": "io.github.example/weather-mcp",
   "description": "Python MCP server for weather data access",
+  "title": "Weather",
   "repository": {
     "url": "https://github.com/example/weather-mcp",
     "source": "github",
@@ -503,6 +507,7 @@ The `dnx` tool ships with the .NET 10 SDK, starting with Preview 6.
   "$schema": "https://static.modelcontextprotocol.io/schemas/2025-09-29/server.schema.json",
   "name": "io.modelcontextprotocol.anonymous/hybrid-mcp",
   "description": "MCP server available as both local package and remote service",
+  "title": "Hybrid",
   "repository": {
     "url": "https://github.com/example/hybrid-mcp",
     "source": "github",
@@ -588,6 +593,7 @@ The `dnx` tool ships with the .NET 10 SDK, starting with Preview 6.
   "$schema": "https://static.modelcontextprotocol.io/schemas/2025-09-29/server.schema.json",
   "name": "io.modelcontextprotocol/text-editor",
   "description": "MCP Bundle server for advanced text editing capabilities",
+  "title": "Text Editor",
   "repository": {
     "url": "https://github.com/modelcontextprotocol/text-editor-mcpb",
     "source": "github"
@@ -632,6 +638,7 @@ Some CLI tools bundle an MCP server, without a standalone MCP package or a publi
   "$schema": "https://static.modelcontextprotocol.io/schemas/2025-09-29/server.schema.json",
   "name": "io.snyk/cli-mcp",
   "description": "MCP server provided by the Snyk CLI",
+  "title": "Snyk",
   "version": "1.1298.0",
   "packages": [
     {

docs/reference/server-json/server.schema.json

@@ -396,6 +396,13 @@
           "minLength": 1,
           "maxLength": 100
         },
+        "title": {
+          "type": "string",
+          "description": "Optional human-readable title or display name for the MCP server. MCP subregistries or clients MAY choose to use this for display purposes.",
+          "example": "Weather API",
+          "minLength": 1,
+          "maxLength": 100
+        },
         "repository": {
           "$ref": "#/definitions/Repository",
           "description": "Optional repository metadata for the MCP server source code. Recommended for transparency and security inspection."