Your task takes place in the current working directory.

You are processing the output of a long-running diagnostic tool. The output is in `tool_output.txt`. Somewhere inside the output there is a line of the form `API_RATE_LIMIT=<value>`. Find that value and report it back to the user.

You may create scratch files if helpful. When you have the answer, respond with a short message that includes the exact line `API_RATE_LIMIT=<value>` and nothing else important.

Do not modify `tool_output.txt`.