Is Custom Search Tool safe?

Custom Search Tool overrides the default search engine and sends all user searches to Yahoo with hardcoded affiliate tracking parameters.

When installed, the extension sets Yahoo as the default search provider via a manifest override. Every search query the user types is appended with partner identifiers (hspart=airfind, hsimp=yhs-searchtool) that attribute the traffic to the extension's operator for affiliate revenue. No other data collection or network communication beyond the search redirect was observed.