[Tiny Agents] Add dummy parameters field to exit loop tools (#1624)

Follow-up PR to #1610.
Some LLM engines (like llama.cpp) strictly validate the `parameters`
field in function definitions, even for tools that take no arguments. To
avoid parsing issues, this PR adds an explicit dummy `parameters` field.
(See: huggingface/huggingface_hub#3218)
✅ I tested the PR with different providers/models to make sure it's
backward compatible.

Author: hanouticelina

packages/mcp-client/src/Agent.ts

@@ -25,13 +25,31 @@ const taskCompletionTool: ChatCompletionInputTool = {
 	function: {
 		name: "task_complete",
 		description: "Call this tool when the task given by the user is complete",
+		parameters: {
+			type: "object",
+			properties: {
+				trigger: {
+					type: "boolean",
+					description: "Set to true to trigger this function",
+				},
+			},
+		},
 	},
 };
 const askQuestionTool: ChatCompletionInputTool = {
 	type: "function",
 	function: {
 		name: "ask_question",
 		description: "Ask a question to the user to get more info required to solve or clarify their problem.",
+		parameters: {
+			type: "object",
+			properties: {
+				trigger: {
+					type: "boolean",
+					description: "Set to true to trigger this function",
+				},
+			},
+		},
 	},
 };
 const exitLoopTools = [taskCompletionTool, askQuestionTool];