Attach Rule/sets to Tools directly, to go in the system prompt

[vachillo]

when using Tools, a lot of times i find myself having to give the Structure specific Rules or Rulesets on how/when/why to use the Tool. Being able to set these directly on the Tool itself, rather than on the Structure or Task, would make it a lot more convenient to work with, make the Tool more reusable, and make the rule content itself more concise by having more assumed context.

ex:

agent = Agent(
    tools=[
        MyCoolTool(),
        DateTimeTool(),
    ],
    rules=[
        Rule("Use the MyCoolTool for questions about ..."),
        Rule("Do not use MyCoolTool for questions about..."),
        Rule("Use the DateTimeTool as the very LAST tool only")
    ]
)

becomes

agent = Agent(
    tools=[
        MyCoolTool(
            rules=[
                Rule("Used for questions about ..."),
                Rule("Not used for questions about..."),
            ]
        ),
        DateTimeTool(
            rules=[
                Rule("Should always be used LAST."),
            ]
        ),
    ],
)

there is a gray area between what goes in the @activity descriptions and what this would be used for, but the user should be able to decide that

even better, being able to create custom Tools and defining a set of default Rules:

@define
class MyCoolTool(BaseTool)
    rules: list[Rule] = field(
        default=[
            Rule("Used for questions about..."),
            Rule("Not used for questions about...")
        ]
    )