mcp-tool-integration

MCP Tool Integration

Overview

Model Context Protocol (MCP) is the standard for connecting AI agents to external tools and context. This skill guides the integration and development of new MCP tools.

When to Use

• You need to access data outside the agent's current context
• You are building custom tools for Claude Desktop or other MCP-compatible clients
• Integrating REST APIs, databases, or local services via MCP

Process

1. Define the Protocol: Choose standard stdio or SSE depending on the deployment environment.
2. Design Tool Schemas: Create clear, descriptive JSON schemas for tool inputs.
3. Implement Handlers: Write the execution logic.
4. Test Locally: Verify tool execution and error handling.
5. Configure Client: Add the MCP server to the agent's configuration file.

Common Rationalizations

Rationalization	Why It Is Wrong
"The handler works, so the tool is done."	Agents rely on schemas, names, and descriptions as much as handler code.
"Errors can just throw."	MCP clients need predictable errors so agents can recover or explain the failure.
"The client config is obvious."	A working server is not useful until the target client can discover and invoke it.

Red Flags

• Tool names or descriptions are vague
• Inputs accept broad strings instead of structured fields
• The handler returns raw internal errors or stack traces
• No local client invocation has been tested

Verification

Before finishing, confirm:

• Tool schemas describe the inputs an agent should actually provide
• Handler success and error paths were exercised locally
• Client configuration is documented and tested
• Secrets, tokens, and local paths are not exposed in tool responses