use_llm in GitHub repo https://github.com/strands-agents

The deprecation warning you're seeing is related to the Strands Agents SDK, which is a model-driven approach for developing AI agents.

The warning indicates that the use_llm function is being deprecated and will be removed in the next major release. The recommended migration path is to replace any calls to use_llm with use_agent to maintain equivalent functionality.

As for the "Tool 'python_repl' not found in parent agent's tool registry" error, this suggests that you're trying to use the python_repl tool, but it hasn't been properly registered with your agent. In Strands Agents, tools need to be explicitly provided to the agent during initialization.

For example, when creating a Strands Agent, you would typically include the tools you want to use like this:

from strands import Agent
from strands_tools import http_request, python_repl

agent = Agent(
model="us.anthropic.claude-sonnet-4-20250514-v1:0",
tools=[http_request, python_repl]
)

Make sure you've imported the python_repl tool and included it in the list of tools when initializing your agent. If you're using nested agents or delegating to sub-agents, you'll need to ensure the tools are properly passed to all agents that need them.
Sources
Using Strands Agents with Claude 4 Interleaved Thinking | AWS Open Source Blog
Building intelligent AI voice agents with Pipecat and Amazon Bedrock – Part 2 | Artificial Intelligence