, with 27.0GB of space still available. If you're concerned about the high usage, you might want to consider cleaning up some files to free up more space." ## How It Works ### Server Capabilities When the server starts, it advertises its capabilities to Claude through the MCP protocol. Here's what Claude sees: ```python @mcp.tool() def get_disk_usage() -> Dict[str, str]: """Get current disk usage information for the system disk Returns: A dictionary containing disk usage information with fields: - device: Device name - total_gb: Total size in GB - used_gb: Used space in GB - available_gb: Available space in GB - reserved_gb: Space reserved by system in GB - percent_used: Usage percentage - mount: Mount point - summary: Human-readable summary of disk usage """ ``` This tells Claude that: 1. The server provides a tool called `get_disk_usage` 2. The tool returns a dictionary with detailed disk information 3. The docstring explains what each field means ### The Complete Claude-MCP Interaction Flow 1. **Initial System Prompt to Claude**: ``` You are Claude, an AI assistant. You have access to these tools: get_disk_usage() -> Dict[str, str] "Get current disk usage information for the system disk" To use this tool, respond with a XML block: get_disk_usage Explain why you need disk usage information ``` 2. **User Query**: ``` User: What is my current disk usage? ``` 3. **Claude's Tool Selection Response**: ``` I'll check your disk usage information. get_disk_usage User has requested current disk usage information. This tool will provide detailed statistics about disk space utilization. ``` 4. **Claude Desktop App → MCP Server**: ```json // HTTP POST to MCP Server { "jsonrpc": "2.0", "method": "invoke", "params": { "tool": "get_disk_usage", "args": {} }, "id": 1 } ``` 5. **MCP Server → Claude Desktop App**: ```json { "jsonrpc": "2.0", "result": { "device": "/dev/disk3s5", "total_gb": "228.0GB", "used_gb": "177.0GB", "available_gb": "27.0GB", "reserved_gb": "24.0GB", "percent_used": "87%", "mount": "/System/Volumes/Data", "summary": "Total: 228.0GB | Used: 177.0GB | Available: 27.0GB | Reserved: 24.0GB | Usage: 87%" }, "id": 1 } ``` 6. **New Request to Claude** (with tool output as context): ``` User: What is my current disk usage? Tool Response: { "device": "/dev/disk3s5", "total_gb": "228.0GB", "used_gb": "177.0GB", "available_gb": "27.0GB", "reserved_gb": "24.0GB", "percent_used": "87%", "mount": "/System/Volumes/Data", "summary": "Total: 228.0GB | Used: 177.0GB | Available: 27.0GB | Reserved: 24.0GB | Usage: 87%" } Provide a helpful response to the user based on this disk usage information. ``` 7. **Claude's Final Response**: ``` Here's your current disk usage information: Total Disk Space: 228.0GB Used Space: 177.0GB Available Space: 27.0GB Reserved Space: 24.0GB Usage Percentage: 87% Mount Point: /System/Volumes/Data Device: /dev/disk3s5 Your disk is currently at 87% capacity, with 27.0GB of space still available. If you're concerned about the high usage, you might want to consider cleaning up some files to free up more space. ``` This shows the complete flow: 1. Claude starts with knowledge of available tools 2. User asks a question 3. Claude recognizes the need for disk info and proposes using the tool 4. After approval, tool response is injected into the conversation 5. Claude processes the raw data into a helpful response ### Technical Implementation ```python # Tool advertisement from server { "tools": [ { "name": "get_disk_usage", "description": "Get current disk usage information for the system disk", "parameters": {}, # No parameters needed "returns": {

Disk Usage MCP Server (Demo)

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