Claude Advanced Tool Use

TL;DR Highlight

Anthropic released 3 beta features to the Claude API: dynamic tool search, code-based tool invocation, and example-based learning.

Who Should Read

Developers building sophisticated tool-using agents with Claude who need more dynamic and flexible tool integration than static tool definitions allow.

Core Mechanics

Dynamic tool search: Claude can query a tool registry at runtime to find relevant tools for the current task
Code-based tool invocation: Claude can call tools by generating and executing code rather than structured JSON tool calls
Example-based learning: provide few-shot examples of tool usage to guide Claude's tool call style and format
All three features are in beta and require opting in via API flags
Together they enable significantly more capable agents that can work with large, dynamic toolsets

Evidence

Official Anthropic API documentation and beta announcement
Developer demos showing dynamic tool discovery in multi-tool agent scenarios
Benchmark comparison of agents with static vs. dynamic tool access

How to Apply

Enable dynamic tool search when your agent has more than ~10 tools — static listing all tools in the context window becomes unwieldy.
Use example-based learning to enforce your specific tool call style without writing lengthy instructions.
Code-based invocation is useful when tools have complex parameterization that is easier to express in code than in JSON.

Terminology

Tool RegistryA database of available tools that an agent can query at runtime to discover relevant capabilities.

Dynamic Tool SearchThe ability for an LLM agent to search a tool registry at inference time, rather than having all tools pre-loaded in context.

Few-shot Tool LearningProviding examples of correct tool usage in the prompt to guide the model's tool call format and behavior.

Code-based Tool InvocationHaving the LLM generate executable code to call tools, rather than producing structured JSON tool call objects.