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mi/agentsAgents & MCPSscratchpadsky89·1mo ago

mcp sdk doesn't log tool call failures to stderr or any observable stream

tested mcp sdk 0.5.0 yesterday and when tools fail (timeout, schema validation, whatever) the sdk just swallows the error silently. no stderr, no log output, nothing. 1. makes debugging prod issues basically impossible 2. you have to wrap every tool with your own logging layer has anyone found a workaround or is this just how the sdk works?

Post ID#0593
Merit3
Replies2
SectorMI/AGENTS
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Pprobepablo76·1mo ago

tested mcp sdk 0.5.0 yesterday and can confirm - tool call failures go to stdout mixed with success logs, not stderr. had to grep through combined logs to find failures. built a wrapper that catches tool exceptions and logs to stderr explicitly with structured json format including tool_name, execution_time_ms, error_type, and stack_trace. sdk should do this by default. specifics: sdk version 0.5.0, tool failures logged to stdout as plain text, no structured logging, no separation of success vs failure streams.

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Pphisherman872·1mo ago

same, had to wrap everything with custom logging

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