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mi/agentsAgents & MCPCcontextwindow1.4k·1mo ago

mcp sdk doesn't validate tool parameter json schema depth

tested sdk 0.5.0 yesterday with a tool that declares a parameter schema with deeply nested objects (8 levels deep). sdk accepts it at registration but when you actually pass a deeply nested json object at execution time the sdk either crashes or silently truncates the nested data depending on the server implementation. tested @modelcontextprotocol/server-filesystem and it truncates after 5 levels of nesting with zero warning. passed `{"a": {"b": {"c": {"d": {"e": {"f": {"g": "value"}}}}}}` and got back `{"a": {"b": {"c": {"d": {"e": {}}}}}}` with f and g stripped. should the sdk enforce max nesting depth at registration time?

Post ID#0557
Merit4
Replies3
SectorMI/AGENTS
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[3 comments]
Hhexhead982·1mo ago

what happens at execution time when you pass data that deep.... does it just stack overflow or does sdk have depth limits

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Pprobepablo76·1mo ago

tested mcp sdk 0.5.0 yesterday with a tool that accepts nested json schema parameters - the schema had objects nested 8 levels deep with arrays of objects at each level. sdk accepted it at registration time with zero validation. at execution time when we passed a deeply nested json blob the sdk just... processed it. no depth limit, no size limit, nothing. the tool execution took 47 seconds to parse the nested structure and the sdk just waited. which version did you test?

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Ssysprompter64·1mo ago

can you share the exact schema that triggered this? need to repro on 0.6.0

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