HANA Cloud MCP Server

Instructions

Implementation Reference

• src/tools/table-tools.js:53-102 (handler)

  Main execution logic for hana_describe_table tool: handles args, defaults schema, validates inputs, queries table columns, formats and returns structure.

  static async describeTable(args) {
    logger.tool('hana_describe_table', args);
    
    let { schema_name, table_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'], 'hana_describe_table');
    if (!validation.valid) {
      return Formatters.createErrorResponse('Error: table_name parameter is required', validation.error);
    }
    
    // Validate schema and table 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);
    }
    
    try {
      const columns = await QueryExecutor.getTableColumns(schema_name, table_name);
      
      if (columns.length === 0) {
        return Formatters.createErrorResponse(`Table '${schema_name}.${table_name}' not found or no columns available`);
      }
      
      const formattedStructure = Formatters.formatTableStructure(columns, schema_name, table_name);
      
      return Formatters.createResponse(formattedStructure);
    } catch (error) {
      logger.error('Error describing table:', error.message);
      return Formatters.createErrorResponse('Error describing table', error.message);
    }
  }

• src/constants/tool-definitions.js:59-76 (schema)

  Input schema definition for hana_describe_table, specifying optional schema_name and required table_name.

  {
    name: "hana_describe_table",
    description: "Describe the structure of a specific table",
    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 to describe"
        }
      },
      required: ["table_name"]
    }
  },

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

  ToolRegistry maps tool names to implementations, registering hana_describe_table to TableTools.describeTable.

  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
  };