mcp: validate tool output #352
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findleyr
reviewed
Aug 22, 2025
findleyr
reviewed
Aug 22, 2025
| _ = outputResolved | ||
| // Validate output schema, if any. | ||
| // Skip if out is nil: we've removed "null" from the output schema, so nil won't validate. | ||
| if v := reflect.ValueOf(out); v.Kind() == reflect.Pointer && v.IsNil() { |
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But reflect.ValueOf(untyped nil) is invalid, no? Should you also add a v.IsValid() check here?
In that case, I'm concerned as to why our tests pass.
| // Skip if out is nil: we've removed "null" from the output schema, so nil won't validate. | ||
| if v := reflect.ValueOf(out); v.Kind() == reflect.Pointer && v.IsNil() { | ||
| } else if err := validateSchema(outputResolved, &out); err != nil { | ||
| return nil, err |
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Wrap this error to say that the tool output failed to validate.
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Validate the handler's returned output against the output schema of a tool.