The phrase "a mere tool to" is correct and usable in written English.
It can be used to describe something that is considered to be a simple or insignificant means to achieve a particular purpose or goal.
Example: "In this project, the software is just a mere tool to facilitate communication among team members."
Alternatives: "a simple means to" or "just an instrument to".
The Obama campaign has transformed donating from a mere tool to generate revenue into a way of participating in an event, a cultural phenomenon.
He isn't actually interested in adaptation, or processes of integration – language is a mere tool to reiterate his dark view of a world in which no one understands each other.
The framing of the American Muslim community as a mere tool to combat terrorism puts an undue pressure and expectation upon Muslim citizens in this country.
Gendo salvaged the remains of his dead wife's soul and body to create Rei, whom he viewed as a mere tool at his disposal to defeat the Angels.
Yet Del Rey's voice might be her least interesting attribute, a mere tool she's utilized to construct a pop career full of deeper provocations: her visual flair (as captured in countless photographs and some instant-classic music videos), her fluid ideas about female archetypes and the distinctive way she toys with the celebrity industrial complex.
Ferrante: First of all, I would not reduce education to a mere tool of emancipation.
The non-contact machining technique has been continuously evolving from a mere tool and die making process to a micro-scale application machining alternative attracting a significant amount of research interests.
King Abdullah -- as his father, King Hussein, before him -- must balance the American support crucial to his survival against the need not to be seen as a mere tool of Washington.
The Internet was a mere tool, and the dream was, as ever, to foster the alchemy that occurs when one person stands inches from another's attempt to make the churning world stand still.
Technology's greatest claim on us, here – and it is a claim that is increasingly making mobile phones more like an extension of our minds and bodies than a mere tool – is its promise of constant connection to our innermost network.
But at the same time, the tradition will not maintain itself: It depends on our commitment to carry on our debates in good faith, to recognize whenever possible the good faith of those with whom we disagree, and to resist the perennial temptation to convert constitutional law into a mere tool of ideological warfare.
