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Invalid 'tools': array too long

When you work with StudioAssist, you may get the error Invalid 'tools': array too long or this error log:

com.kms.katalon.ai.core.model.exception.StudioAssistLlmApiRuntimeException:
INVALID_ARGUMENT:
com.katalon.gpt.extension.api.gpt.ApiInvalidRequestException: com.azure.core.exception.HttpResponseException: Status code 400, "{ "error": { "message": "Invalid 'tools': array too long. Expected an array with maximum length 128, but got an array with length 129 instead.", "type": "invalid_request_error", "param": "tools", "code": "array_above_max_length" } }"

Cause​

Some AI service providers like OpenAI enforce a limit of 128 MCP tools per request. Exceeding this limit by enabling more than 128 tools causes this error:

selected tool number exceed limit

Remedy​

Disable tools you don't need.

  1. Go to Agent mode settings menu.
studioassist agent mode mcp tool setting button
  1. In MCP Tool tab, find and disable the tools you don't need (3), or disable a whole MCP server (2). Your progress will be auto-saved.
features and buttons for configuring MCP servers and tools
  1. Close the settings menu, and try again.
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