Definition
What is Tool Description Routing? — Plain-Language AI Definition
The mechanism by which Claude selects which tool to call based on the natural-language description provided in the tool definition.
What is Tool Description Routing?
Tool description routing is how Claude decides which tool to use. Each tool has a description field written in natural language. Claude reads these descriptions and matches the user's intent to the most appropriate tool.
Why It Matters
The description is the single most important factor in whether Claude picks the right tool. A vague description leads to wrong tool calls. A clear, specific description leads to reliable routing.
Best Practices
- Be specific: "Search the product catalog by name or SKU" beats "Search for things"
- State what the tool does, not how it works internally
- Include when to use it for disambiguation
- Avoid overlap between tool descriptions
Key Takeaway
Tool descriptions are not documentation for developers -- they are routing instructions for the model.
Learn This in Practice
Move from definition to application with guides and resources that show how this concept appears in real AI workflows.
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