Struct ToolDef 

pub struct ToolDef {
    pub name: String,
    pub description: String,
    pub parameters_schema: Value,
    pub handler: Box<dyn Fn(Value) -> BoxFuture<'static, Result<Value, ToolError>> + Send + Sync>,
}

A registered tool with its async handler.

parameters_schema must already be normalized via schema::for_structured_output before registration. The handler must own all captured state (no &references — wrap shared state in Arc<T> to satisfy the 'static bound).

Fields

name: String

The tool name. Must match what the LLM will call.

description: String

Human-readable description of what the tool does.

parameters_schema: Value

JSON Schema for the tool’s input parameters.

Must be pre-normalized via schema::for_structured_output. The LLM-generated input is passed as-is to the handler — handler implementations are responsible for validating their own inputs before privileged actions (T-166-03).

handler: Box<dyn Fn(Value) -> BoxFuture<'static, Result<Value, ToolError>> + Send + Sync>

The async handler closure.

Receives the LLM-generated serde_json::Value and returns either a JSON result or a ToolError with a model-legible message.