HANA Cloud MCP Server

Instructions

Implementation Reference

• src/tools/index-tools.js:82-132 (handler)

  The handler function IndexTools.describeIndex that implements the core logic for the hana_describe_index tool: validates parameters, fetches index details via QueryExecutor, formats output, and handles errors.

  static async describeIndex(args) {
    logger.tool('hana_describe_index', args);
    
    let { schema_name, table_name, index_name } = args || {};
    
    // Use default schema if not provided
    if (!schema_name) {
      if (config.hasDefaultSchema()) {
        schema_name = config.getDefaultSchema();
        logger.info(`Using default schema: ${schema_name}`);
      } else {
        return Formatters.createErrorResponse(
          'Schema name is required', 
          'Please provide schema_name parameter or set HANA_SCHEMA environment variable'
        );
      }
    }
    
    // Validate required parameters
    const validation = Validators.validateRequired(args, ['table_name', 'index_name'], 'hana_describe_index');
    if (!validation.valid) {
      return Formatters.createErrorResponse('Error: table_name and index_name parameters are required', validation.error);
    }
    
    // Validate schema, table, and index names
    const schemaValidation = Validators.validateSchemaName(schema_name);
    if (!schemaValidation.valid) {
      return Formatters.createErrorResponse('Invalid schema name', schemaValidation.error);
    }
    
    const tableValidation = Validators.validateTableName(table_name);
    if (!tableValidation.valid) {
      return Formatters.createErrorResponse('Invalid table name', tableValidation.error);
    }
    
    const indexValidation = Validators.validateIndexName(index_name);
    if (!indexValidation.valid) {
      return Formatters.createErrorResponse('Invalid index name', indexValidation.error);
    }
    
    try {
      const results = await QueryExecutor.getIndexDetails(schema_name, table_name, index_name);
      
      const formattedDetails = Formatters.formatIndexDetails(results, schema_name, table_name, index_name);
      
      return Formatters.createResponse(formattedDetails);
    } catch (error) {
      logger.error('Error describing index:', error.message);
      return Formatters.createErrorResponse('Error describing index', error.message);
    }
  }

• src/constants/tool-definitions.js:96-116 (schema)

  The input schema definition for hana_describe_index, specifying properties and required fields: table_name and index_name.

    name: "hana_describe_index",
    description: "Describe the structure of a specific index",
    inputSchema: {
      type: "object",
      properties: {
        schema_name: {
          type: "string",
          description: "Name of the schema containing the table (optional)"
        },
        table_name: {
          type: "string",
          description: "Name of the table containing the index"
        },
        index_name: {
          type: "string",
          description: "Name of the index to describe"
        }
      },
      required: ["table_name", "index_name"]
    }
  },

• src/tools/index.js:14-24 (registration)

  Tool registration mapping 'hana_describe_index' to IndexTools.describeIndex in the TOOL_IMPLEMENTATIONS object used by ToolRegistry.

  const TOOL_IMPLEMENTATIONS = {
    hana_show_config: ConfigTools.showConfig,
    hana_test_connection: ConfigTools.testConnection,
    hana_show_env_vars: ConfigTools.showEnvVars,
    hana_list_schemas: SchemaTools.listSchemas,
    hana_list_tables: TableTools.listTables,
    hana_describe_table: TableTools.describeTable,
    hana_list_indexes: IndexTools.listIndexes,
    hana_describe_index: IndexTools.describeIndex,
    hana_execute_query: QueryTools.executeQuery
  };