MCP Integration Usage Guide

Overview

Use the MCP integration plugin to discover and execute tools provided by external MCP servers. This skill enables you to access legal databases, query APIs, search databases, and integrate with any service that provides an MCP interface.

The plugin provides a unified mcp tool with two actions:

list - Discover available tools from all connected servers
call - Execute a specific tool with parameters

Process

🔍 Phase 1: Tool Discovery

1.1 Check Available Tools

Always start by listing available tools to see what MCP servers are connected and what capabilities they provide.

Action:

{
  tool: "mcp",
  args: {
    action: "list"
  }
}

Response structure:

[
  {
    "id": "server:toolname",
    "server": "server-name",
    "name": "tool-name", 
    "description": "What this tool does",
    "inputSchema": {
      "type": "object",
      "properties": {...},
      "required": [...]
    }
  }
]

1.2 Understand Tool Schemas

For each tool, examine:

id: Format is "server:toolname" - split on : to get server and tool names
description: Understand what the tool does
inputSchema: JSON Schema defining parameters
- properties: Available parameters with types and descriptions
- required: Array of mandatory parameter names

1.3 Match Tools to User Requests

Common tool naming patterns:

search_* - Find or search operations (e.g., search_statute, search_users)
get_* - Retrieve specific data (e.g., get_statute_full_text, get_weather)
query - Execute queries (e.g., database:query)
analyze_* - Analysis operations (e.g., analyze_law)
resolve_* - Resolve references (e.g., resolve_citation)

🎯 Phase 2: Tool Execution

2.1 Validate Parameters

Before calling a tool:

Identify all required parameters from inputSchema.required
Verify parameter types match schema (string, number, boolean, array, object)
Check for constraints (minimum, maximum, enum values, patterns)
Ensure you have necessary information from the user

2.2 Construct Tool Call

Action:

{
  tool: "mcp",
  args: {
    action: "call",
    server: "<server-name>",
    tool: "<tool-name>",
    args: {
      // Tool-specific parameters from inputSchema
    }
  }
}

Example - Korean legal search:

{
  tool: "mcp",
  args: {
    action: "call",
    server: "kr-legal",
    tool: "search_statute",
    args: {
      query: "연장근로 수당",
      limit: 5
    }
  }
}

2.3 Parse Response

Tool responses follow this structure:

{
  "content": [
    {
      "type": "text",
      "text": "JSON string or text result"
    }
  ],
  "isError": false
}

For JSON responses:

const data = JSON.parse(response.content[0].text);
// Access data.result, data.results, or direct properties

🔄 Phase 3: Multi-Step Workflows

3.1 Chain Tool Calls

For complex requests, execute multiple tools in sequence:

Example - Legal research workflow:

Search - search_statute to find relevant laws
Retrieve - get_statute_full_text for complete text
Analyze - analyze_law for interpretation
Precedents - search_case_law for related cases

Each step uses output from the previous step to inform the next call.

3.2 Maintain Context

Between tool calls:

Extract relevant information from each response
Use extracted data as parameters for subsequent calls
Build up understanding progressively
Present synthesized results to user

⚠ Phase 4: Error Handling

4.1 Common Errors

"Tool not found: server:toolname"

Cause: Server not connected or tool doesn't exist
Solution: Run action: "list" to verify available tools
Check spelling of server and tool names

"Invalid arguments for tool"

Cause: Missing required parameter or wrong type
Solution: Review inputSchema from list response
Ensure all required parameters provided with correct types

"Server connection failed"

Cause: MCP server not running or unreachable
Solution: Inform user service is temporarily unavailable
Suggest alternatives if possible

4.2 Error Response Format

Errors return:

{
  "content": [{"type": "text", "text": "Error: message"}],
  "isError": true
}

Handle gracefully:

Explain what went wrong clearly
Don't expose technical implementation details
Suggest next steps or alternatives
Don't retry excessively

Complete Example

User Request: "Find Korean laws about overtime pay"

Step 1: Discover tools

{tool: "mcp", args: {action: "list"}}

Response shows kr-legal:search_statute with:

Required: query (string)
Optional: limit (number), category (string)

Step 2: Execute search

{
  tool: "mcp",
  args: {
    action: "call",
    server: "kr-legal",
    tool: "search_statute",
    args: {
      query: "연장근로 수당",
      category: "노동법",
      limit: 5
    }
  }
}

Step 3: Parse and present

const data = JSON.parse(response.content[0].text);
// Present data.results to user

User-facing response:

Found 5 Korean statutes about overtime pay:

1. 근로기준법 제56조 (연장·야간 및 휴일 근로)
   - Overtime work requires 50% premium
   
2. 근로기준법 제50조 (근로시간)
   - Standard working hours: 40 hours per week

Would you like me to retrieve the full text of any statute?

Quick Reference

List Tools

{tool: "mcp", args: {action: "list"}}

Call Tool

{
  tool: "mcp",
  args: {
    action: "call",
    server: "server-name",
    tool: "tool-name",
    args: {param1: "value1"}
  }
}

Essential Patterns

Tool ID parsing: "server:toolname" → split on : for server and tool names

Parameter validation: Check inputSchema.required and inputSchema.properties[param].type

Response parsing: JSON.parse(response.content[0].text) for JSON responses

Error detection: Check response.isError === true

Reference Documentation

Core Documentation

Plugin README: README.md - Installation and configuration
Real Example: REAL_EXAMPLE_KR_LEGAL.md - Working kr-legal setup
API Reference: API.md - Technical API details
Configuration: CONFIGURATION.md - Server configuration guide
Troubleshooting: TROUBLESHOOTING.md - Common issues and solutions

Usage Examples

Examples Collection: EXAMPLES.md - 13 real-world examples including:
- Legal research workflows
- Database queries
- Weather service integration
- Multi-step complex workflows
- Error handling patterns

Remember: Always start with action: "list" when uncertain about available tools.