Overview
Tools are part of the agent's operating system. A browser tool may expose actions such as:
- Click an element.
- Drag an item.
- Read a console message.
- Open a page.
- Take a screenshot.
- Enter text.
The agent needs descriptions of these actions so it knows what capabilities are available and how to use them. Those descriptions consume tokens.
The same is true for file tools, search tools, command-line tools, model endpoints, and APIs. A large toolset gives the agent more power but also increases the size of the operating context.
This creates another design trade-off:
- Too few tools limit the agent's ability to act.
- Too many always-loaded tools consume context and may make selection more difficult.
The solution is similar to skill management: expose what is necessary, keep descriptions compact, and load specialized capabilities when the task requires them.