Allow Client#call_tool to accept a tool name#266
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koic merged 1 commit intomodelcontextprotocol:mainfrom Mar 23, 2026
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## Motivation and Context `Client#call_tool` previously required an `MCP::Client::Tool` object to call a tool. This made the API harder to use compared to other MCP SDK implementations, which accept a tool name string directly: - Python SDK: `session.call_tool(name, arguments)` accepts a name string. https://github.com/modelcontextprotocol/python-sdk/blob/v1.26.0/src/mcp/client/session.py#L370 - TypeScript SDK: `client.callTool({ name, arguments })` accepts a name string. https://github.com/modelcontextprotocol/typescript-sdk/blob/ccb78f2/packages/client/src/client/client.ts#L834 ## How Has This Been Tested? Updated existing tests and added new tests. ## Breaking Change No. This change adds a `name:` parameter so callers can pass a tool name string directly without looking up a `Tool` object first. The existing `tool:` parameter continues to work for backward compatibility.
atesgoral
approved these changes
Mar 22, 2026
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Motivation and Context
Client#call_toolpreviously required anMCP::Client::Toolobject to call a tool. This made the API harder to use compared to other MCP SDK implementations, which accept a tool name string directly:session.call_tool(name, arguments)accepts a name string. https://github.com/modelcontextprotocol/python-sdk/blob/v1.26.0/src/mcp/client/session.py#L370client.callTool({ name, arguments })accepts a name string. https://github.com/modelcontextprotocol/typescript-sdk/blob/ccb78f2/packages/client/src/client/client.ts#L834How Has This Been Tested?
Updated existing tests and added new tests.
Breaking Change
No. This change adds a
name:parameter so callers can pass a tool name string directly without looking up aToolobject first. The existingtool:parameter continues to work for backward compatibility.Types of changes
Checklist
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