refactor: update tool handling to use ToolDefinition and simplify SessionRequestBuilder

Author: brunoborges

src/main/java/com/github/copilot/sdk/CopilotSession.java

@@ -546,7 +546,7 @@ void registerTools(List<ToolDefinition> tools) {
         toolHandlers.clear();
         if (tools != null) {
             for (ToolDefinition tool : tools) {
-                toolHandlers.put(tool.getName(), tool);
+                toolHandlers.put(tool.name(), tool);
             }
         }
     }

src/main/java/com/github/copilot/sdk/RpcHandlerDispatcher.java

@@ -129,7 +129,7 @@ private void handleToolCall(JsonRpcClient rpc, String requestId, JsonNode params
                 }
 
                 ToolDefinition tool = session.getTool(toolName);
-                if (tool == null || tool.getHandler() == null) {
+                if (tool == null || tool.handler() == null) {
                     var result = new ToolResultObject().setTextResultForLlm("Tool '" + toolName + "' is not supported.")
                             .setResultType("failure").setError("tool '" + toolName + "' not supported");
                     rpc.sendResponse(Long.parseLong(requestId), Map.of("result", result));
@@ -139,7 +139,7 @@ private void handleToolCall(JsonRpcClient rpc, String requestId, JsonNode params
                 var invocation = new ToolInvocation().setSessionId(sessionId).setToolCallId(toolCallId)
                         .setToolName(toolName).setArguments(arguments);
 
-                tool.getHandler().invoke(invocation).thenAccept(result -> {
+                tool.handler().invoke(invocation).thenAccept(result -> {
                     try {
                         ToolResultObject toolResult;
                         if (result instanceof ToolResultObject tr) {

src/main/java/com/github/copilot/sdk/SessionRequestBuilder.java

@@ -4,13 +4,10 @@
 
 package com.github.copilot.sdk;
 
-import java.util.stream.Collectors;
-
 import com.github.copilot.sdk.json.CreateSessionRequest;
 import com.github.copilot.sdk.json.ResumeSessionConfig;
 import com.github.copilot.sdk.json.ResumeSessionRequest;
 import com.github.copilot.sdk.json.SessionConfig;
-import com.github.copilot.sdk.json.ToolDef;
 
 /**
  * Builds JSON-RPC request objects from session configuration.
@@ -41,10 +38,7 @@ static CreateSessionRequest buildCreateRequest(SessionConfig config) {
         request.setModel(config.getModel());
         request.setSessionId(config.getSessionId());
         request.setReasoningEffort(config.getReasoningEffort());
-        request.setTools(config.getTools() != null
-                ? config.getTools().stream().map(t -> new ToolDef(t.getName(), t.getDescription(), t.getParameters()))
-                        .collect(Collectors.toList())
-                : null);
+        request.setTools(config.getTools());
         request.setSystemMessage(config.getSystemMessage());
         request.setAvailableTools(config.getAvailableTools());
         request.setExcludedTools(config.getExcludedTools());
@@ -83,10 +77,7 @@ static ResumeSessionRequest buildResumeRequest(String sessionId, ResumeSessionCo
 
         request.setModel(config.getModel());
         request.setReasoningEffort(config.getReasoningEffort());
-        request.setTools(config.getTools() != null
-                ? config.getTools().stream().map(t -> new ToolDef(t.getName(), t.getDescription(), t.getParameters()))
-                        .collect(Collectors.toList())
-                : null);
+        request.setTools(config.getTools());
         request.setSystemMessage(config.getSystemMessage());
         request.setAvailableTools(config.getAvailableTools());
         request.setExcludedTools(config.getExcludedTools());

src/main/java/com/github/copilot/sdk/json/CreateSessionRequest.java

@@ -35,7 +35,7 @@ public final class CreateSessionRequest {
     private String reasoningEffort;
 
     @JsonProperty("tools")
-    private List<ToolDef> tools;
+    private List<ToolDefinition> tools;
 
     @JsonProperty("systemMessage")
     private SystemMessageConfig systemMessage;
@@ -115,12 +115,12 @@ public void setReasoningEffort(String reasoningEffort) {
     }
 
     /** Gets the tools. @return the tool definitions */
-    public List<ToolDef> getTools() {
+    public List<ToolDefinition> getTools() {
         return tools == null ? null : Collections.unmodifiableList(tools);
     }
 
     /** Sets the tools. @param tools the tool definitions */
-    public void setTools(List<ToolDef> tools) {
+    public void setTools(List<ToolDefinition> tools) {
         this.tools = tools;
     }
 

src/main/java/com/github/copilot/sdk/json/ResumeSessionRequest.java

@@ -36,7 +36,7 @@ public final class ResumeSessionRequest {
     private String reasoningEffort;
 
     @JsonProperty("tools")
-    private List<ToolDef> tools;
+    private List<ToolDefinition> tools;
 
     @JsonProperty("systemMessage")
     private SystemMessageConfig systemMessage;
@@ -119,12 +119,12 @@ public void setReasoningEffort(String reasoningEffort) {
     }
 
     /** Gets the tools. @return the tool definitions */
-    public List<ToolDef> getTools() {
+    public List<ToolDefinition> getTools() {
         return tools == null ? null : Collections.unmodifiableList(tools);
     }
 
     /** Sets the tools. @param tools the tool definitions */
-    public void setTools(List<ToolDef> tools) {
+    public void setTools(List<ToolDefinition> tools) {
         this.tools = tools;
     }
 

src/main/java/com/github/copilot/sdk/json/ToolDef.java

@@ -6,6 +6,7 @@
 
 import java.util.Map;
 
+import com.fasterxml.jackson.annotation.JsonIgnore;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 
@@ -39,149 +40,21 @@
  * 		});
  * }</pre>
  *
+ * @param name
+ *            the unique name of the tool
+ * @param description
+ *            a description of what the tool does
+ * @param parameters
+ *            the JSON Schema defining the tool's parameters
+ * @param handler
+ *            the handler function to execute when invoked
  * @see SessionConfig#setTools(java.util.List)
  * @see ToolHandler
  * @since 1.0.0
  */
 @JsonInclude(JsonInclude.Include.NON_NULL)
-public class ToolDefinition {
-
-    @JsonProperty("name")
-    private String name;
-
-    @JsonProperty("description")
-    private String description;
-
-    @JsonProperty("parameters")
-    private Object parameters;
-
-    private transient ToolHandler handler;
-
-    /**
-     * Creates an empty tool definition.
-     * <p>
-     * Use the setter methods to configure the tool.
-     */
-    public ToolDefinition() {
-    }
-
-    /**
-     * Creates a tool definition with all properties.
-     *
-     * @param name
-     *            the unique name of the tool
-     * @param description
-     *            a description of what the tool does
-     * @param parameters
-     *            the JSON Schema defining the tool's parameters
-     * @param handler
-     *            the handler function to execute when invoked
-     */
-    public ToolDefinition(String name, String description, Object parameters, ToolHandler handler) {
-        this.name = name;
-        this.description = description;
-        this.parameters = parameters;
-        this.handler = handler;
-    }
-
-    /**
-     * Gets the tool name.
-     *
-     * @return the unique name of the tool
-     */
-    public String getName() {
-        return name;
-    }
-
-    /**
-     * Sets the tool name.
-     * <p>
-     * The name should be unique within a session and follow naming conventions
-     * similar to function names (e.g., "get_user", "search_files").
-     *
-     * @param name
-     *            the unique name of the tool
-     * @return this tool definition for method chaining
-     */
-    public ToolDefinition setName(String name) {
-        this.name = name;
-        return this;
-    }
-
-    /**
-     * Gets the tool description.
-     *
-     * @return the description of what the tool does
-     */
-    public String getDescription() {
-        return description;
-    }
-
-    /**
-     * Sets the tool description.
-     * <p>
-     * The description helps the AI understand when and how to use the tool. Be
-     * clear and specific about the tool's purpose and any constraints.
-     *
-     * @param description
-     *            the description of what the tool does
-     * @return this tool definition for method chaining
-     */
-    public ToolDefinition setDescription(String description) {
-        this.description = description;
-        return this;
-    }
-
-    /**
-     * Gets the parameter schema.
-     *
-     * @return the JSON Schema for the tool's parameters
-     */
-    public Object getParameters() {
-        return parameters;
-    }
-
-    /**
-     * Sets the parameter schema.
-     * <p>
-     * The schema should follow JSON Schema format and define the structure of
-     * arguments the tool accepts. This is typically a {@code Map} with "type",
-     * "properties", and "required" fields.
-     *
-     * @param parameters
-     *            the JSON Schema for the tool's parameters
-     * @return this tool definition for method chaining
-     */
-    public ToolDefinition setParameters(Object parameters) {
-        this.parameters = parameters;
-        return this;
-    }
-
-    /**
-     * Gets the tool handler.
-     *
-     * @return the handler function that executes when the tool is invoked
-     */
-    public ToolHandler getHandler() {
-        return handler;
-    }
-
-    /**
-     * Sets the tool handler.
-     * <p>
-     * The handler is called when the assistant invokes this tool. It receives a
-     * {@link ToolInvocation} with the arguments and should return a
-     * {@code CompletableFuture} with the result.
-     *
-     * @param handler
-     *            the handler function
-     * @return this tool definition for method chaining
-     * @see ToolHandler
-     */
-    public ToolDefinition setHandler(ToolHandler handler) {
-        this.handler = handler;
-        return this;
-    }
+public record ToolDefinition(@JsonProperty("name") String name, @JsonProperty("description") String description,
+        @JsonProperty("parameters") Object parameters, @JsonIgnore ToolHandler handler) {
 
     /**
      * Creates a tool definition with a JSON schema for parameters.

src/main/java/com/github/copilot/sdk/json/ToolDefinition.java

@@ -80,7 +80,7 @@ void testBuildResumeRequestWithTools() {
 
         assertNotNull(request.getTools());
         assertEquals(1, request.getTools().size());
-        assertEquals("my_tool", request.getTools().get(0).getName());
+        assertEquals("my_tool", request.getTools().get(0).name());
     }
 
     @Test