Struct A2aDelegateTool 

pub struct A2aDelegateTool { /* private fields */ }

Tool for delegating a task to another agent discovered by capability.

Usage flow:

1. Agent calls a2a_delegate with a description and required capability.
2. The tool queries the AgentCardRegistry for agents with that capability.
3. If found, it delegates the task via A2A and waits for the result.
4. Returns the execution result to the calling agent.

Implementations

impl A2aDelegateTool

pub fn new(a2a: Arc<A2AProtocol>, agent_id: AgentId) -> Self

Create a new A2A delegate tool.

pub fn from_kernel(kernel: &KernelHandle, agent_id: AgentId) -> Self

Create an A2aDelegateTool from a [KernelHandle].

Extracts the A2A protocol from the kernel’s a2a facade.

Trait Implementations

impl AgentTool for A2aDelegateTool

fn name(&self) -> &str

Tool name (used in function calls)

fn label(&self) -> &str

Human-readable label

fn description(&self) -> &str

Description for the model

fn parameters_schema(&self) -> Value

JSON Schema for parameters

fn execute<'life0, 'life1, 'life2, 'async_trait>( &'life0 self, _tool_call_id: &'life1 str, params: Value, _shutdown: Option<Receiver<()>>, _ctx: &'life2 ToolContext, ) -> Pin<Box<dyn Future<Output = Result<AgentToolResult, ToolError>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait, 'life2: 'async_trait,

Execute the tool with the given tool call ID and parameters.

fn essential(&self) -> bool

Whether this tool is essential (cannot be disabled). Essential tools: read, write, edit, bash, grep, find, ls Optional tools: web_search, github, subagent, etc.

fn on_progress(&self, _callback: Arc<dyn Fn(String) + Sync + Send>)

Called with progress updates during execution. Tools can override this to emit streaming updates.

fn to_definition(&self) -> ToolDefinition

Convert to ToolDefinition

impl Debug for A2aDelegateTool

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

Formats the value using the given formatter.