You can enable targeted instrumentation for HTTP 400 errors caused by invalid parameters. This configuration provides deeper visibility into parameter validation failures without introducing broad DEBUG noise.

To enable targeted diagnostics for invalid parameter errors, apply this configuration:
{
  "runtime": {
    "middleware": { "validation_diagnostics": { "enabled": true } }
  },
  "logging": {
    "loggers": { "validation.diagnostics": "INFO" }
  }
}
The following log line appears:
{"level":"info","logger":"validation.diagnostics",
"msg":"invalid_params: method=tool.invoke 
message=Invalid params: missing required field 'id' arg_keys=['filter','top']"}
Here are the important details about how invalid parameter diagnostics are sanitized to protect sensitive information. Understanding these santization aspects helps you interpret logs correctly and maintain security.
Aspect Description
Logged content Only the error message text (truncated to 300 characters) and the list of top-level argument keys
Excluded content No raw argument values are logged
Recommendation Revert the logger level to INFO after completing diagnosis