Advancing Tool Support - Part 1

[ThomasVitale]

• Defined new APIs consolidating the “tool” naming as opposed to the current “function”, aligning with the industry and solving the confusion between “function tool” and “Java Function”: ToolCallback and ToolCallingChatOptions. They extend the current ones to ensure backward compatibility, but FunctionCallback and FunctionCallingOptions can be considered deprecated.
• Enhanced support for methods as tools, introducing support for declarative Tool-annotated methods via MethodToolCallback and MethodToolCallbackProvider (deprecating the existing MethodInvokingFunctionCallback).
• Improved tool execution logic with granular support for returning the result directly to the client and exception handling.
• Improved JSON Schema generation and parsing logic, consolidating the usage of the victools/jsonschema-generator library and dropping the non-maintained Jackson JSON Schema Module. This makes it possible to use tools with input lists/arrays, which the latter library was not supporting.
• Extended ChatClient API with new methods tools() and toolCallbacks(). The existing functions() methods can be considered deprecated.

Relates to gh-2049

Full working example showing how things work after the changes in this PR: https://github.com/arconia-io/arconia-examples/tree/main/arconia-ai/tools-ollama

Partial example:

class MyTools {

    @Tool("Get the list of books written by the given author available in the library")
    List<Book> booksByAuthor(String author) {
        return bookService.getBooksByAuthor(new Author(author));
    }

}

@GetMapping("/chat")
String chat(String authorName) {
    return chatClient.prompt()
            .user("What books written by %s are available in the library?".formatted(authorName))
            .tools(myTools)
            .call()
            .content();
}