chore!: remove deprecated Example processor

PiperOrigin-RevId: 880745271

Author: Mateusz Krawiec

core/src/main/java/com/google/adk/agents/LlmAgent.java

@@ -45,8 +45,6 @@
 import com.google.adk.agents.ConfigAgentUtils.ConfigurationException;
 import com.google.adk.codeexecutors.BaseCodeExecutor;
 import com.google.adk.events.Event;
-import com.google.adk.examples.BaseExampleProvider;
-import com.google.adk.examples.Example;
 import com.google.adk.flows.llmflows.AutoFlow;
 import com.google.adk.flows.llmflows.BaseLlmFlow;
 import com.google.adk.flows.llmflows.SingleFlow;
@@ -97,8 +95,6 @@ public enum IncludeContents {
   private final List<Object> toolsUnion;
   private final ImmutableList<BaseToolset> toolsets;
   private final Optional<GenerateContentConfig> generateContentConfig;
-  // TODO: Remove exampleProvider field - examples should only be provided via ExampleTool
-  private final Optional<BaseExampleProvider> exampleProvider;
   private final IncludeContents includeContents;
 
   private final boolean planning;
@@ -132,7 +128,6 @@ protected LlmAgent(Builder builder) {
     this.globalInstruction =
         requireNonNullElse(builder.globalInstruction, new Instruction.Static(""));
     this.generateContentConfig = Optional.ofNullable(builder.generateContentConfig);
-    this.exampleProvider = Optional.ofNullable(builder.exampleProvider);
     this.includeContents = requireNonNullElse(builder.includeContents, IncludeContents.DEFAULT);
     this.planning = builder.planning != null && builder.planning;
     this.maxSteps = Optional.ofNullable(builder.maxSteps);
@@ -180,7 +175,6 @@ public static class Builder extends BaseAgent.Builder<Builder> {
     private Instruction globalInstruction;
     private ImmutableList<Object> toolsUnion;
     private GenerateContentConfig generateContentConfig;
-    private BaseExampleProvider exampleProvider;
     private IncludeContents includeContents;
     private Boolean planning;
     private Integer maxSteps;
@@ -253,26 +247,6 @@ public Builder generateContentConfig(GenerateContentConfig generateContentConfig
       return this;
     }
 
-    // TODO: Remove these example provider methods and only use ExampleTool for providing examples.
-    // Direct example methods should be deprecated in favor of using ExampleTool consistently.
-    @CanIgnoreReturnValue
-    public Builder exampleProvider(BaseExampleProvider exampleProvider) {
-      this.exampleProvider = exampleProvider;
-      return this;
-    }
-
-    @CanIgnoreReturnValue
-    public Builder exampleProvider(List<Example> examples) {
-      this.exampleProvider = (unused) -> examples;
-      return this;
-    }
-
-    @CanIgnoreReturnValue
-    public Builder exampleProvider(Example... examples) {
-      this.exampleProvider = (unused) -> ImmutableList.copyOf(examples);
-      return this;
-    }
-
     @CanIgnoreReturnValue
     public Builder includeContents(IncludeContents includeContents) {
       this.includeContents = includeContents;
@@ -640,10 +614,18 @@ protected void validate() {
                   + " transfer.");
         }
         if (this.toolsUnion != null && !this.toolsUnion.isEmpty()) {
-          throw new IllegalArgumentException(
-              "Invalid config for agent "
-                  + this.name
-                  + ": if outputSchema is set, tools must be empty.");
+          boolean hasOtherTools =
+              this.toolsUnion.stream()
+                  .anyMatch(
+                      tool ->
+                          !(tool instanceof BaseTool baseTool)
+                              || !baseTool.name().equals("example_tool"));
+          if (hasOtherTools) {
+            throw new IllegalArgumentException(
+                "Invalid config for agent "
+                    + this.name
+                    + ": if outputSchema is set, tools must be empty.");
+          }
         }
       }
     }
@@ -812,11 +794,6 @@ public Optional<GenerateContentConfig> generateContentConfig() {
     return generateContentConfig;
   }
 
-  // TODO: Remove this getter - examples should only be provided via ExampleTool
-  public Optional<BaseExampleProvider> exampleProvider() {
-    return exampleProvider;
-  }
-
   public IncludeContents includeContents() {
     return includeContents;
   }

core/src/main/java/com/google/adk/examples/ExampleUtils.java

@@ -64,6 +64,9 @@ public final class ExampleUtils {
    * @return string representation of the examples block.
    */
   private static String convertExamplesToText(List<Example> examples) {
+    if (examples.isEmpty()) {
+      return "";
+    }
     StringBuilder examplesStr = new StringBuilder();
 
     // super header

core/src/main/java/com/google/adk/flows/llmflows/Examples.java

@@ -32,7 +32,6 @@ public class SingleFlow extends BaseLlmFlow {
           new Identity(),
           new Compaction(),
           new Contents(),
-          new Examples(),
           CodeExecution.requestProcessor);
 
   protected static final ImmutableList<ResponseProcessor> RESPONSE_PROCESSORS =

core/src/main/java/com/google/adk/flows/llmflows/SingleFlow.java

@@ -85,7 +85,9 @@ public Completable processLlmRequest(
       return Completable.complete();
     }
 
-    llmRequestBuilder.appendInstructions(ImmutableList.of(examplesBlock));
+    if (!examplesBlock.isEmpty()) {
+      llmRequestBuilder.appendInstructions(ImmutableList.of(examplesBlock));
+    }
     // Delegate to BaseTool to keep any declaration bookkeeping (none for this tool)
     return super.processLlmRequest(llmRequestBuilder, toolContext);
   }

core/src/main/java/com/google/adk/tools/ExampleTool.java

@@ -35,6 +35,7 @@
 import com.google.adk.agents.Callbacks.OnModelErrorCallback;
 import com.google.adk.agents.Callbacks.OnToolErrorCallback;
 import com.google.adk.events.Event;
+import com.google.adk.examples.Example;
 import com.google.adk.models.LlmRegistry;
 import com.google.adk.models.LlmRequest;
 import com.google.adk.models.LlmResponse;
@@ -46,6 +47,7 @@
 import com.google.adk.testing.TestUtils.EchoTool;
 import com.google.adk.tools.BaseTool;
 import com.google.adk.tools.BaseToolset;
+import com.google.adk.tools.ExampleTool;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
 import com.google.errorprone.annotations.CanIgnoreReturnValue;
@@ -649,4 +651,30 @@ private SpanData findSpanByName(List<SpanData> spans, String name) {
         .findFirst()
         .orElseThrow(() -> new AssertionError("Span not found: " + name));
   }
+
+  @Test
+  public void run_withExampleTool_doesNotAddFunctionDeclarations() {
+    ExampleTool tool =
+        ExampleTool.builder()
+            .addExample(
+                Example.builder()
+                    .input(Content.fromParts(Part.fromText("qin")))
+                    .output(ImmutableList.of(Content.fromParts(Part.fromText("qout"))))
+                    .build())
+            .build();
+
+    Content modelContent = Content.fromParts(Part.fromText("Real LLM response"));
+    TestLlm testLlm = createTestLlm(createLlmResponse(modelContent));
+    LlmAgent agent = createTestAgentBuilder(testLlm).tools(tool).build();
+    InvocationContext invocationContext = createInvocationContext(agent);
+
+    var unused = agent.runAsync(invocationContext).toList().blockingGet();
+
+    assertThat(testLlm.getRequests()).hasSize(1);
+    LlmRequest request = testLlm.getRequests().get(0);
+
+    assertThat(request.config().isPresent()).isTrue();
+    var config = request.config().get();
+    assertThat(config.tools().isPresent()).isFalse();
+  }
 }

core/src/test/java/com/google/adk/agents/LlmAgentTest.java

@@ -49,17 +49,7 @@ public List<Example> getExamples(String query) {
   @Test
   public void buildFewShotFewShot_noExamples() {
     TestExampleProvider exampleProvider = new TestExampleProvider(ImmutableList.of());
-    String expected =
-        """
-        <EXAMPLES>
-        Begin few-shot
-        The following are examples of user queries and model responses using the available tools.
-
-        End few-shot
-        Now, try to follow these examples and complete the following conversation
-        <EXAMPLES>\
-        """;
-    assertThat(ExampleUtils.buildExampleSi(exampleProvider, "test query")).isEqualTo(expected);
+    assertThat(ExampleUtils.buildExampleSi(exampleProvider, "test query")).isEmpty();
   }
 
   @Test

core/src/test/java/com/google/adk/examples/ExampleUtilsTest.java

@@ -305,4 +305,30 @@ static final class WrongTypeProviderHolder {
 
     private WrongTypeProviderHolder() {}
   }
+
+  @Test
+  public void declaration_isEmpty() {
+    ExampleTool tool = ExampleTool.builder().build();
+    assertThat(tool.declaration().isPresent()).isFalse();
+  }
+
+  @Test
+  public void processLlmRequest_doesNotAddFunctionDeclarations() {
+    ExampleTool tool = ExampleTool.builder().addExample(makeExample("qin", "qout")).build();
+    InvocationContext ctx = buildInvocationContext();
+    LlmRequest.Builder builder = LlmRequest.builder().model("gemini-2.0-flash");
+
+    tool.processLlmRequest(builder, ToolContext.builder(ctx).build()).blockingAwait();
+    LlmRequest updated = builder.build();
+
+    if (updated.config().isPresent()) {
+      var config = updated.config().get();
+      if (config.tools().isPresent()) {
+        var tools = config.tools().get();
+        boolean hasFunctionDeclarations =
+            tools.stream().anyMatch(t -> t.functionDeclarations().isPresent());
+        assertThat(hasFunctionDeclarations).isFalse();
+      }
+    }
+  }
 }