search_engine_batch with Google engine returns raw HTML instead of JSON intermittently #167

Description

When using the MCP tool with , the response intermittently returns raw HTML instead of parsed JSON. This happens roughly 50% of the time.

Error

Unexpected non-JSON response from Bright Data for search_engine_batch

The error originates inside the compiled .mcpb bundle (), not in any downstream consumer. The bundle appears to pass through the raw Google SERP HTML when the underlying API returns a non-JSON response, without validating or retrying.

Related

• Existing issue MCP - Invalid JSON: EOF while parsing a string at line 1 column 51268 #74 reports a similar JSON parse failure ("Invalid JSON: EOF while parsing a string at line 1 column 51268")
• (single query) with Google also exhibits this behavior
• Bing and Yandex engines work reliably through the same tools

Workarounds for consumers

• Use or for search results
• Use the tool as an alternative search method

Suggested fix

The MCP server should validate that the Google SERP API response is valid JSON before returning it to the caller. If the response is not JSON, it should either retry the request or return a clear error indicating the upstream API returned unexpected content.