google-adk-kotlin-core/com.google.adk.kt.tools/BaseTool

BaseTool

abstract class BaseTool(val name: String, val description: String, val isLongRunning: Boolean = false, val customMetadata: Map<String, Any> = emptyMap())

Abstract base class for defining and executing tools.

Inheritors

Constructors

BaseTool

constructor(name: String, description: String, isLongRunning: Boolean = false, customMetadata: Map<String, Any> = emptyMap())

Types

Companion

object Companion

Properties

customMetadata

val customMetadata: Map<String, Any>

The custom metadata of the tool.

description

val description: String

The description of the tool.

isLongRunning

val isLongRunning: Boolean = false

Whether the tool's final result will be delivered out-of-band. When true, the framework marks the call as long-running and uses the tool's return value as the function-response payload. Returning Unit means "no response yet": the FR event is suppressed so the function-call event (which carries the call id in longRunningToolIds and is thus the turn's final response) ends the turn without re-invoking the model. A non-Unit return -- including an explicit empty Map -- is treated as a real response and emitted. (Unit suppression aligns with Python; Java instead always emits {}.) The longRunningToolIds id also drives the resumable-mode pause gate so the invocation can be resumed later via a user-injected function-response.

name

val name: String

The name of the tool.

Functions

open fun close()

declaration

abstract fun declaration(): FunctionDeclaration?

Returns the underlying function declaration.

processLlmRequest

open suspend fun processLlmRequest(toolContext: ToolContext, llmRequest: LlmRequest): LlmRequest

Processes the LLM request before it is sent.

run

abstract suspend fun run(context: ToolContext, args: Map<String, Any>): Any

Executes the tool and returns its result.