Summarize tool call outputs using tool specific summarizers (#3745)

packages/core/src/tools/tools.ts

@@ -5,6 +5,7 @@
  */
 
 import { FunctionDeclaration, PartListUnion, Schema } from '@google/genai';
+import { Summarizer, defaultSummarizer } from '../utils/summarizer.js';
 
 /**
  * Interface representing the base Tool functionality
@@ -43,6 +44,16 @@ export interface Tool<
    */
   canUpdateOutput: boolean;
 
+  /**
+   * A function that summarizes the result of the tool execution.
+   */
+  summarizer?: Summarizer;
+
+  /**
+   * Whether the tool's display output should be summarized
+   */
+  shouldSummarizeDisplay?: boolean;
+
   /**
    * Validates the parameters for the tool
    * Should be called from both `shouldConfirmExecute` and `execute`
@@ -98,6 +109,8 @@ export abstract class BaseTool<
    * @param isOutputMarkdown Whether the tool's output should be rendered as markdown
    * @param canUpdateOutput Whether the tool supports live (streaming) output
    * @param parameterSchema JSON Schema defining the parameters
+   * @param summarizer Function to summarize the tool's output
+   * @param shouldSummarizeDisplay Whether the tool's display output should be summarized
    */
   constructor(
     readonly name: string,
@@ -106,6 +119,8 @@ export abstract class BaseTool<
     readonly parameterSchema: Schema,
     readonly isOutputMarkdown: boolean = true,
     readonly canUpdateOutput: boolean = false,
+    readonly summarizer: Summarizer = defaultSummarizer,
+    readonly shouldSummarizeDisplay: boolean = false,
   ) {}
 
   /**
@@ -173,6 +188,11 @@ export abstract class BaseTool<
 }
 
 export interface ToolResult {
+  /**
+   * A short, one-line summary of the tool's action and result.
+   * e.g., "Read 5 files", "Wrote 256 bytes to foo.txt"
+   */
+  summary?: string;
   /**
    * Content meant to be included in LLM history.
    * This should represent the factual outcome of the tool execution.