Tool-Level Checks

from agentscope.tool import ToolBase
from agentscope.permission import PermissionContext, PermissionDecision, PermissionBehavior

class MyTool(ToolBase):
    name = "MyTool"
    # Static default. For tools whose answer depends on input, leave
    # this as the conservative default and override check_read_only().
    is_read_only = False

    async def check_read_only(self, tool_input: dict) -> bool:
        """Optional: dynamic read-only check.

        Defaults to returning self.is_read_only. Override when whether
        an invocation modifies state depends on the input. The engine
        calls this for the read-only fast path in every mode (the
        auto-allow that runs before check_permissions).
        """
        return tool_input.get("operation") in {"list", "describe", "get"}

    async def check_permissions(
        self,
        tool_input: dict,
        context: PermissionContext,
    ) -> PermissionDecision:
        target = tool_input.get("target")

        # Custom safety check: block operations on production resources.
        # Setting bypass_immune=True makes this ASK survive allow rules
        # in DEFAULT/ACCEPT_EDITS/DONT_ASK; BYPASS still skips it.
        if target and target.startswith("prod-"):
            return PermissionDecision(
                behavior=PermissionBehavior.ASK,
                message=f"Operation targets production resource: {target}",
                decision_reason="Safety check: production resource",
                bypass_immune=True,
            )

        # Return PASSTHROUGH to let the engine continue with rules/mode
        return PermissionDecision(behavior=PermissionBehavior.PASSTHROUGH)