Tool Use & Function Calling
Can Claude call the same tool multiple times in one turn?
QUICK ANSWER
Yes. If Claude needs to fetch multiple independent data points, it will return multiple tool_use blocks referencing the same tool name but with distinct arguments and unique tool_use_ids.
Behavioral Mechanics
For example, if you ask: 'Compare the weather in Chicago and Seattle', Claude will output two separate tool calls in the same response block: one for Chicago and one for Seattle. Your executor must loop through the content array, execute both calls, and return two tool_result blocks matching the IDs.
Verified against: Anthropic Tool Execution Spec