What is Tool use?
Verified 5 August 2026
The mechanism that connects a model to anything outside its weights. The model receives tool descriptions, decides which to call and with what arguments, and continues with the result.
Tool design matters more than it looks. A tool that exposes twenty parameters invites the model to guess badly at nineteen of them; a tool with two parameters and sensible pinned defaults produces far better results. Most retrieval quality problems in agents are filter problems in disguise.
How unlob handles this: Integrations
Common questions
What is Tool use?
Tool use lets a model invoke external functions — search, calculation, database queries — and incorporate the results into its reasoning.
How does Tool use work in practice?
Tool design matters more than it looks. A tool that exposes twenty parameters invites the model to guess badly at nineteen of them; a tool with two parameters and sensible pinned defaults produces far better results. Most retrieval quality problems in agents are filter problems in disguise.
See it working
The free tier is 10,000 requests a month with no card — enough to test any of this against your own queries.