kotlin-sdk-core/io.modelcontextprotocol.kotlin.sdk.types/Tool

Tool

data class Tool(val name: String, val inputSchema: ToolSchema, val description: String? = null, val outputSchema: ToolSchema? = null, val title: String? = null, val annotations: ToolAnnotations? = null, val icons: List<Icon>? = null, val meta: JsonObject? = null) : WithMeta(source)

Definition for a tool the client can call.

Tools allow servers to expose functionality that can be invoked by clients and LLMs. Each tool has a name, description, and schema defining its input (and optionally output) parameters.

Display name precedence order: title → annotations.title → name

Constructors

Tool

constructor(name: String, inputSchema: ToolSchema, description: String? = null, outputSchema: ToolSchema? = null, title: String? = null, annotations: ToolAnnotations? = null, icons: List<Icon>? = null, meta: JsonObject? = null)

Properties

_meta

open val ~~_meta~~: JsonObject

annotations

val annotations: ToolAnnotations?

Optional additional tool information providing hints about tool behavior. All properties in ToolAnnotations are hints and not guaranteed to provide a faithful description of tool behavior.

description

val description: String?

A human-readable description of the tool and when to use it. Clients can use this to improve the LLM's understanding of available tools. It can be thought of like a "hint" to the model.

icons

val icons: List<Icon>?

Optional set of sized icons that clients can display in their user interface. Clients MUST support at least PNG and JPEG formats. Clients SHOULD also support SVG and WebP formats.

inputSchema

val inputSchema: ToolSchema

A JSON Schema object defining the expected parameters for the tool. Must be an object type schema. Defines what arguments the tool accepts.