chore: update docs

docs/core_docs/docs/integrations/tools/google_finance.mdx

@@ -11,7 +11,7 @@ exchange rates, and other investment-related information from Google Finance.
 ## Setup
 Before using the tool, ensure you have your API key. You can create an account on [SerpAPI](https://serpapi.com/users/sign_in) and obtain your API key
 under **Your Private API Key** in your account dashboard. The Google Finance API is included in the free plan offered by SerpAPI.
-Once you have the key, set it as `process.env.SERPAPI_API_KEY` or pass it as the `apiKey` argument when initializing the tool.
+Once you have the key, set it to the `SERPAPI_API_KEY` environment variable or pass it in as the `apiKey` argument when initializing the tool.
 
 ## Usage