fix operator precedence in calculate tool

Author: yinebebt

README.md

@@ -1,11 +1,11 @@
 # MCP Calculator Server
 
-A Model Context Protocol (MCP) server that provides calculator functionality.
+A Model Context Protocol (MCP) server that provides calculator functionality with robust mathematical operations.
 
 ## Features
 
 ### Tools
-- **calculate**: Mathematical operations with proper operator precedence
+- **calculate**: Mathematical operations with proper operator precedence, parentheses support, and scientific notation
 - **random_number**: Generate random numbers within specified ranges
 
 ### Resources
@@ -26,10 +26,18 @@ A Model Context Protocol (MCP) server that provides calculator functionality.
 
 ## Usage
 
-```sh
+```bash
+# Install
 go install github.com/yinebebt/mcp-calculator-server@latest
 
-TRANSPORT=stdio ./mcp-calculator-server
+# Run with stdio
+TRANSPORT=stdio mcp-calculator-server
+
+# Run with HTTP
+mcp-calculator-server
+
+# Test
+go test
 ```
 
 ### MCP Client Configuration
@@ -42,4 +50,11 @@ For testing with MCP Client:
     "TRANSPORT": "stdio"
   }
 }
-```
+```
+
+## Mathematical Features
+
+- **Operator precedence**: `2+3*4 = 14`
+- **Parentheses**: `(2+3)*4 = 20`
+- **Scientific notation**: `1e2 = 100`
+- **Error detection**: Division by zero, invalid syntax, unmatched parentheses