Docs MCP Server

Instructions

Implementation Reference

• src/index.js:178-203 (handler)

  The primary handler function that performs the actual documentation search by calling the 'search' function from '@probelabs/probe' with the query and data directory.

  async executeDocsSearch(args) {
  	try {
  		// Always use the configured data directory
  		const searchPath = config.dataDir;
  
  		// Create a clean options object
  		const options = {
  			path: searchPath,
  			query: args.query,
  			maxTokens: 10000 // Set default maxTokens
  			// Removed filesOnly, maxResults, session
  		};
  
  		console.error("Executing search with options:", JSON.stringify(options, null, 2));
  
  		// Call search with the options object
  		const result = await search(options);
  		return result;
  	} catch (error) {
  		console.error('Error executing docs search:', error);
  		throw new McpError(
  			ErrorCode.MethodNotFound,
  			`Error executing docs search: ${error.message || String(error)}`
  		);
  	}
  }

• src/index.js:102-116 (schema)

  Defines the JSON schema for the tool's input parameters: required 'query' string and optional 'page' number.

  inputSchema: {
  	type: 'object',
  	properties: {
  		query: {
  			type: 'string',
  			description: 'Elasticsearch query string. Focus on keywords and use ES syntax (e.g., "install AND guide", "configure OR setup", "api NOT internal").',
  		},
  		page: {
  			type: 'number',
  			description: 'Optional page number for pagination of results (e.g., 1, 2, 3...). Default is 1.',
  			default: 1, // Set a default value
  		}
  	},
  	required: ['query'] // 'page' is optional
  },

• src/index.js:97-119 (registration)

  Registers the 'search_docs' tool (using config.toolName) with its description and schema in the MCP ListToolsRequestSchema handler.

  this.server.setRequestHandler(ListToolsRequestSchema, async () => ({
  	tools: [
  		{
  			name: config.toolName, // Use configured tool name
  			description: config.toolDescription, // Use configured description
  			inputSchema: {
  				type: 'object',
  				properties: {
  					query: {
  						type: 'string',
  						description: 'Elasticsearch query string. Focus on keywords and use ES syntax (e.g., "install AND guide", "configure OR setup", "api NOT internal").',
  					},
  					page: {
  						type: 'number',
  						description: 'Optional page number for pagination of results (e.g., 1, 2, 3...). Default is 1.',
  						default: 1, // Set a default value
  					}
  				},
  				required: ['query'] // 'page' is optional
  			},
  		},
  	],
  }));

• src/index.js:121-170 (registration)

  Handles MCP CallToolRequestSchema, validates tool name matches 'search_docs', and invokes the executeDocsSearch handler.

  	this.server.setRequestHandler(CallToolRequestSchema, async (request) => {
  		// Check against the configured tool name
  		if (request.params.name !== config.toolName) {
  			throw new McpError(
  				ErrorCode.MethodNotFound,
  				`Unknown tool: ${request.params.name}. Expected: ${config.toolName}`
  			);
  		}
  
  		try {
  			// Log the incoming request for debugging
  			console.error(`Received request for tool: ${request.params.name}`);
  			console.error(`Request arguments: ${JSON.stringify(request.params.arguments)}`);
  
  			// Ensure arguments is an object
  			if (!request.params.arguments || typeof request.params.arguments !== 'object') {
  				throw new Error("Arguments must be an object");
  			}
  
  			const args = request.params.arguments;
  
  			// Validate required fields
  			if (!args.query) {
  				throw new Error("Query is required in arguments");
  			}
  
  			const result = await this.executeDocsSearch(args);
  
  			return {
  				content: [
  					{
  						type: 'text',
  						text: result,
  					},
  				],
  			};
  		} catch (error) {
  			console.error(`Error executing ${request.params.name}:`, error);
  			return {
  				content: [
  					{
  						type: 'text',
  						text: `Error executing ${request.params.name}: ${error instanceof Error ? error.message : String(error)}`,
  					},
  				],
  				isError: true,
  			};
  		}
  	});
  }

• src/config.js:27-30 (helper)

  Default configuration for the tool name and description, loaded and used throughout the server.

  // MCP Tool configuration
  toolName: 'search_docs',
  toolDescription: 'Search documentation using the probe search engine.',