tool search
A tool retrieval mechanism proposed by Anthropic that reduces context token overhead by deferring the loading of tool definitions and retrieving them on demand. It addresses the problem of MCP tool definitions consuming a large amount of context.
Timeline (last 90 days)
The Anthropic API's tool search tool marks tools with `defer_loading: true`; the definitions are still transmitted with the tools array, but by default the model sees at most the five tools returned by search each time, which Anthropic says typically reduces definition tokens by more than 85%.
Tool search is typically implemented using vector embedding technology, retrieving the most relevant tools by semantic similarity and injecting them into the context.
All Facts (2)
The Anthropic API's tool search tool marks tools with `defer_loading: true`; the definitions are still transmitted with the tools array, but by default the model sees at most the five tools returned by search each time, which Anthropic says typically reduces definition tokens by more than 85%.
50%UnverifiedTool search is typically implemented using vector embedding technology, retrieving the most relevant tools by semantic similarity and injecting them into the context.
50%