Call a Golem tool from Rust

#[tool_definition] generates a <Tool>Client. Its async methods return Result<T, ToolError<E>>, where E is the tool’s declared error type:

use golem_rust::agentic::ToolError;
 
let client = EchoClient::default();
match client.echo("hello".to_string()).await {
    Ok(value) => println!("{value}"),
    Err(ToolError::Tool(error)) => eprintln!("declared tool error: {error:?}"),
    Err(error) => eprintln!("tool invocation failed: {error}"),
}

The default client targets the definition’s tool name. Use the generated named-target constructor only when deployment assigns another tool registration name. Do not treat protocol errors as the tool’s declared domain error. Drop or finish any stream handles according to the generated method signature.