Unverified50% confidenceDecision RuleExact time
When throwing exceptions in MCP tools, ToolError should be used instead of ordinary ValueError, because ToolError lets the model see the explicit reason and return value, whereas ordinary exceptions may cause the Agent to see only 'tool execution failed' or even trigger meaningless automatic retries.
1
Sources
50%
Confidence
Long-term
Relevance
10/12/2026
First Seen
Sources
Related Entities
Related Claims
Unverified当某个MCP工具未被正确触发时，暂时关闭其他MCP工具减少干扰后重新运行，往往能帮助模型识别到正确的工具75% similarUnverifiedWrite a tool once in an MCP Server, and the Agent can connect via stdio or streamable HTTP, and when errors occur, ToolError should be used first.73% similarVerifiedMCP defines a standard response mechanism for errors occurring during tool calls.72% similarUnverifiedThe tool has a built-in function for pinning MCP tool definitions, and issues a warning when a connected MCP server subsequently modifies its tool definitions.71% similarUnverifiedMCP's classification standard for Tools is not based on whether they read or write, but on whether they need to execute a piece of logic based on input parameters71% similar
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