Trait ToolHandler 

pub trait ToolHandler: Send + Sync {
    // Required methods
    fn list_tools(
        &self,
        ctx: &Context<'_>,
    ) -> impl Future<Output = Result<Vec<Tool>, McpError>> + Send;
    fn call_tool(
        &self,
        name: &str,
        args: Value,
        ctx: &Context<'_>,
    ) -> impl Future<Output = Result<ToolOutput, McpError>> + Send;

    // Provided method
    fn on_tools_changed(&self) -> impl Future<Output = ()> + Send { ... }
}

Handler for tool-related operations.

Implement this trait to expose tools that AI assistants can call.

Required Methods

fn list_tools( &self, ctx: &Context<'_>, ) -> impl Future<Output = Result<Vec<Tool>, McpError>> + Send

List all available tools.

This is called when the client requests the tool list.

fn call_tool( &self, name: &str, args: Value, ctx: &Context<'_>, ) -> impl Future<Output = Result<ToolOutput, McpError>> + Send

Call a tool with the given arguments.

Arguments

• name - The name of the tool to call
• args - The arguments as a JSON value
• ctx - The request context

Provided Methods

fn on_tools_changed(&self) -> impl Future<Output = ()> + Send

Called when a tool’s definition has changed.

Override this to dynamically add/remove/update tools.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementations on Foreign Types

impl<T: ToolHandler> ToolHandler for Arc<T>

fn list_tools( &self, ctx: &Context<'_>, ) -> impl Future<Output = Result<Vec<Tool>, McpError>> + Send

fn call_tool( &self, name: &str, args: Value, ctx: &Context<'_>, ) -> impl Future<Output = Result<ToolOutput, McpError>> + Send

fn on_tools_changed(&self) -> impl Future<Output = ()> + Send

Implementors

impl ToolHandler for ToolService