Attribute Macro tool 

#[tool]

#[tool] Attribute Macro

Generates a Tool implementation for annotated functions:

1. Creates struct wrapper with function
2. Implements Tool trait with:
   • name(): Function name
   • arguments(): JSON schema from doc comments
   • call(): Type-safe argument parsing

Example

use promptrs::{tool, Tooling};

#[tool]
/// Calculator tool
/// a: First number
/// b: Second number
/// operation: +, -, *, /
fn calculate(a: f64, b: f64, operation: String) -> String {
    match operation.as_str() {
        "+" => (a + b).to_string(),
        "-" => (a - b).to_string(),
        "*" => (a * b).to_string(),
        "/" => a / b > 0.0 ? (a / b).to_string() : "Division by zero".into(),
        _ => "Invalid operation".into(),
    }
}

let tooling = Tooling::new().add(calculate);
let args = Arguments::from_value(json!({
    "a": 5.5,
    "b": 2.5,
    "operation": "*"
}));

let result = tooling.call("calculate", &args).unwrap();
println!("Result: {}", result); // 13.75

Documentation Comments

Use /// name: Description to:

1. Create parameter documentation in JSON schema
2. Provide user-facing parameter descriptions
3. Enable parameter auto-completion in development tools