fix: resolve additional mypy type errors

- Fix tool_usage.py: proper type annotations for result and fingerprint metadata
- Fix lite_agent.py: proper Union type for guardrail callable accepting both LiteAgentOutput and TaskOutput
- Add missing return type annotations to task_output_storage_handler.py methods
- Fix crew.py: replace Json generic check with str, remove unused type:ignore and redundant cast

src/crewai/crew.py

@@ -273,7 +273,7 @@ class Crew(FlowTrackable, BaseModel):
         """
 
         # TODO: Improve typing
-        return json.loads(v) if isinstance(v, Json) else v
+        return json.loads(v) if isinstance(v, str) else v
 
     @model_validator(mode="after")
     def set_private_attrs(self) -> Self:
@@ -641,7 +641,7 @@ class Crew(FlowTrackable, BaseModel):
 
             for agent in self.agents:
                 agent.i18n = i18n
-                agent.crew = self  # type: ignore[attr-defined]
+                agent.crew = self
                 agent.set_knowledge(crew_embedder=self.embedder)
                 # TODO: Create an AgentFunctionCalling protocol for future refactoring
                 if not agent.function_calling_llm:  # type: ignore # "BaseAgent" has no attribute "function_calling_llm"
@@ -983,7 +983,7 @@ class Crew(FlowTrackable, BaseModel):
         if hasattr(task_agent, "get_delegation_tools"):
             delegation_tools = task_agent.get_delegation_tools(agents)
             # Cast delegation_tools to the expected type for _merge_tools
-            return self._merge_tools(tools, cast(list[BaseTool], delegation_tools))
+            return self._merge_tools(tools, delegation_tools)
         return cast(list[BaseTool], tools)
 
     def _add_multimodal_tools(

src/crewai/lite_agent.py

@@ -5,6 +5,7 @@ from collections.abc import Callable
 from typing import (
     Any,
     Optional,
+    Union,
     cast,
     get_args,
     get_origin,
@@ -39,6 +40,7 @@ from crewai.events.types.logging_events import AgentLogsExecutionEvent
 from crewai.flow.flow_trackable import FlowTrackable
 from crewai.llm import LLM
 from crewai.llms.base_llm import BaseLLM
+from crewai.task import TaskOutput
 from crewai.tools.base_tool import BaseTool
 from crewai.tools.structured_tool import CrewStructuredTool
 from crewai.utilities import I18N
@@ -185,8 +187,8 @@ class LiteAgent(FlowTrackable, BaseModel):
     _messages: list[dict[str, str]] = PrivateAttr(default_factory=list)
     _iterations: int = PrivateAttr(default=0)
     _printer: Printer = PrivateAttr(default_factory=Printer)
-    _guardrail: Optional[Callable[[LiteAgentOutput], tuple[bool, Any]]] = PrivateAttr(
-        default=None
+    _guardrail: Optional[Callable[[LiteAgentOutput | TaskOutput], tuple[bool, Any]]] = (
+        PrivateAttr(default=None)
     )
     _guardrail_retry_count: int = PrivateAttr(default=0)
 

src/crewai/tools/tool_usage.py

@@ -199,7 +199,7 @@ class ToolUsage:
 
         started_at = time.time()
         from_cache = False
-        result = None  # type: ignore
+        result: str | None = None
 
         if self.tools_handler and self.tools_handler.cache:
             result = self.tools_handler.cache.read(
@@ -243,7 +243,7 @@ class ToolUsage:
                     try:
                         acceptable_args = tool.args_schema.model_json_schema()[
                             "properties"
-                        ].keys()  # type: ignore
+                        ].keys()
                         arguments = {
                             k: v
                             for k, v in calling.arguments.items()
@@ -668,7 +668,7 @@ class ToolUsage:
 
         return event_data
 
-    def _add_fingerprint_metadata(self, arguments: dict) -> dict:
+    def _add_fingerprint_metadata(self, arguments: dict[str, Any]) -> dict[str, Any]:
         """Add fingerprint metadata to tool arguments if available.
 
         Args:

src/crewai/utilities/task_output_storage_handler.py

@@ -33,7 +33,7 @@ class TaskOutputStorageHandler:
     def __init__(self) -> None:
         self.storage = KickoffTaskOutputsSQLiteStorage()
 
-    def update(self, task_index: int, log: dict[str, Any]):
+    def update(self, task_index: int, log: dict[str, Any]) -> None:
         saved_outputs = self.load()
         if saved_outputs is None:
             raise ValueError("Logs cannot be None")
@@ -60,7 +60,7 @@ class TaskOutputStorageHandler:
         task_index: int,
         inputs: dict[str, Any] | None = None,
         was_replayed: bool = False,
-    ):
+    ) -> None:
         inputs = inputs or {}
         self.storage.add(task, output, task_index, was_replayed, inputs)