mcp-capability-declarator

Agent Building

Generate MCP capability declarations from tool and resource inventory with proper versioning and feature flags.

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Source SKILL.md: https://github.com/a5c-ai/babysitter/blob/HEAD/library/specializations/cli-mcp-development/skills/mcp-capability-declarator/SKILL.md

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MCP Capability Declarator

Generate MCP capability declarations from tool/resource inventory.

Capabilities

Generate capability declarations from inventory
Create initialization options
Set up feature flags
Implement capability negotiation
Document server capabilities
Generate capability tests

Usage

Invoke this skill when you need to:

Declare MCP server capabilities
Generate initialization options
Document supported features
Implement capability negotiation

Inputs

Parameter	Type	Required	Description
serverName	string	Yes	Server name
version	string	Yes	Server version
tools	array	No	Tool capabilities
resources	array	No	Resource capabilities
prompts	array	No	Prompt capabilities

Generated Patterns

TypeScript Capability Declaration

import { ServerCapabilities, InitializationOptions } from '@modelcontextprotocol/sdk/types.js';

// Server metadata
export const SERVER_INFO = {
  name: 'my-mcp-server',
  version: '1.0.0',
} as const;

// Capability declarations
export const CAPABILITIES: ServerCapabilities = {
  tools: {
    // Tool capabilities
    listChanged: true,
  },
  resources: {
    // Resource capabilities
    subscribe: true,
    listChanged: true,
  },
  prompts: {
    // Prompt capabilities
    listChanged: true,
  },
  logging: {},
};

// Tool definitions
export const TOOL_DEFINITIONS = [
  {
    name: 'search_files',
    description: 'Search for files matching a pattern',
    inputSchema: {
      type: 'object',
      properties: {
        pattern: { type: 'string', description: 'Glob pattern' },
        path: { type: 'string', description: 'Base path' },
      },
      required: ['pattern'],
    },
  },
  {
    name: 'read_file',
    description: 'Read contents of a file',
    inputSchema: {
      type: 'object',
      properties: {
        path: { type: 'string', description: 'File path' },
      },
      required: ['path'],
    },
  },
] as const;

// Resource templates
export const RESOURCE_TEMPLATES = [
  {
    uriTemplate: 'file:///{path}',
    name: 'File',
    description: 'Access file contents',
    mimeType: 'text/plain',
  },
] as const;

// Create initialization options
export function createInitializationOptions(): InitializationOptions {
  return {
    serverInfo: SERVER_INFO,
    capabilities: CAPABILITIES,
  };
}

// Capability documentation
export const CAPABILITY_DOCS = `
# ${SERVER_INFO.name} v${SERVER_INFO.version}

## Supported Capabilities

### Tools
${TOOL_DEFINITIONS.map(t => `- **${t.name}**: ${t.description}`).join('\n')}

### Resources
- File access via \`file:///\` URI scheme
- Resource subscription support
- List change notifications

### Prompts
- Dynamic prompt templates
- List change notifications

## Feature Flags
- Tool list change notifications: enabled
- Resource subscriptions: enabled
`;

Python Capability Declaration

from dataclasses import dataclass
from typing import List, Dict, Any

@dataclass
class ServerInfo:
    name: str = "my-mcp-server"
    version: str = "1.0.0"

@dataclass
class ToolDefinition:
    name: str
    description: str
    input_schema: Dict[str, Any]

TOOL_DEFINITIONS: List[ToolDefinition] = [
    ToolDefinition(
        name="search_files",
        description="Search for files matching a pattern",
        input_schema={
            "type": "object",
            "properties": {
                "pattern": {"type": "string"},
                "path": {"type": "string"},
            },
            "required": ["pattern"],
        },
    ),
]

CAPABILITIES = {
    "tools": {"listChanged": True},
    "resources": {"subscribe": True, "listChanged": True},
    "prompts": {"listChanged": True},
    "logging": {},
}

def create_initialization_options() -> dict:
    return {
        "serverInfo": {
            "name": ServerInfo.name,
            "version": ServerInfo.version,
        },
        "capabilities": CAPABILITIES,
    }

Workflow

Inventory tools - List all tools
Inventory resources - List all resources
Define capabilities - Feature flags
Generate declarations - Capability objects
Create init options - Initialization
Document capabilities - API docs

Target Processes

mcp-server-bootstrap
mcp-tool-implementation
mcp-tool-documentation