Struct FunctionTool 

pub struct FunctionTool<Input, Output, Handler> { /* private fields */ }

A typed asynchronous Rust function exposed through the canonical Tool boundary.

Implementations

impl<Input, Output, Handler> FunctionTool<Input, Output, Handler>

where Input: JsonSchema, Output: JsonSchema,

pub fn new( name: impl Into<String>, description: impl Into<String>, handler: Handler, ) -> Self

Creates a typed Tool with generated input and output JSON Schemas.

The default effect is EffectClass::Pure and the default risk is RiskLevel::Low. Callers must explicitly override these values for functions that read or modify external state.

impl<Input, Handler> FunctionTool<Input, ToolOutput, Handler>

where Input: JsonSchema,

pub fn new_rich( name: impl Into<String>, description: impl Into<String>, handler: Handler, ) -> Self

Creates a typed Tool whose handler returns canonical rich content.

Unlike Self::new, this constructor preserves the returned ToolOutput instead of serializing it into JSON text. The default output schema is permissive because rich presentation content and optional structured content are validated by the canonical Tool boundary rather than one generated Rust output type.

impl<Input, Output, Handler> FunctionTool<Input, Output, Handler>

pub const fn capability_id(self, id: CapabilityId) -> Self

Replaces the stable capability identity.

pub fn version(self, version: impl Into<String>) -> Self

Sets the semantic Tool contract version.

pub const fn effect(self, effect: EffectClass) -> Self

Declares external-effect behavior.

pub const fn risk(self, risk: RiskLevel) -> Self

Declares policy risk.

pub fn metadata(self, key: impl Into<String>, value: Value) -> Self

Adds host-only namespaced metadata.

pub fn output_schema(self, schema: Value) -> Self

Replaces the successful output schema.

This is primarily useful for rich Tools that attach typed structured_content alongside media. The registry compiles and enforces the schema before exposing a successful result to an Agent.

Trait Implementations

impl<Input, Output, Handler> Debug for FunctionTool<Input, Output, Handler>

fn fmt(&self, formatter: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<Input, Output, Handler, HandlerFuture> Tool for FunctionTool<Input, Output, Handler>

where Input: DeserializeOwned + JsonSchema + Send + 'static, Output: JsonSchema + Serialize + Send + 'static, Handler: Fn(Input, ToolContext) -> HandlerFuture + Send + Sync, HandlerFuture: Future<Output = Result<Output, ToolError>> + Send + 'static,

fn descriptor(&self) -> &ToolDescriptor

Returns the tool’s immutable semantic contract.

fn invoke( &self, input: Value, context: ToolContext, ) -> ToolFuture<'_, Result<ToolOutput, ToolError>>

Executes one invocation.

impl<Input, Handler, HandlerFuture> Tool for FunctionTool<Input, ToolOutput, Handler>

where Input: DeserializeOwned + JsonSchema + Send + 'static, Handler: Fn(Input, ToolContext) -> HandlerFuture + Send + Sync, HandlerFuture: Future<Output = Result<ToolOutput, ToolError>> + Send + 'static,

fn descriptor(&self) -> &ToolDescriptor

Returns the tool’s immutable semantic contract.

fn invoke( &self, input: Value, context: ToolContext, ) -> ToolFuture<'_, Result<ToolOutput, ToolError>>

Executes one invocation.