Inspect the response body before calling a Claude web search successful. HTTP 200 can accompany a tool-level error, so transport success and successful evidence retrieval need separate fields in an API measurement record.
What the provider documents
Anthropic's web search documentation describes search errors inside a successful HTTP response. It also distinguishes an error from a successful search with no results.
Those distinctions matter for technical marketers using API observations. A tool failure should not silently become evidence that the brand was absent from a completed search.
Review the layers in order
- Record the HTTP status and request identifier when available.
- Inspect tool-use and tool-result content blocks.
- Check for a search error object and its documented code.
- Inspect the final text and citation structures.
- Decide whether the answer meets your declared measurement validity rule.
Illustrative example: a request returns HTTP 200 and an answer, but its search result reports a usage-limit error. The answer exists, yet the requested search did not complete. Label the search-grounded observation incomplete rather than describing it as a clean negative visibility result.
Keep empty results distinct
A successful search with an empty result list is a different observation from an unavailable tool. Preserve the empty result state and inspect whether the generated answer makes unsupported assumptions.
Do not automatically classify all uncited answers as failures. The correct validity rule depends on whether your benchmark requires a grounded answer and whether the response actually attempted search. Declare that rule before reviewing brand outcomes.
Retry without duplicating the measurement
Keep the failed attempt and link a controlled retry to the same planned slot. State whether the retry replaces missing evidence or becomes an additional repetition. Check current provider guidance for the error class before retrying; repeated requests are not a repair for every configuration or permission problem.
If the issue changes the collection period or provider mix, show that limitation in the report. Do not merge a delayed partial recovery into an apparently uninterrupted series.
This article describes API diagnostic handling. It does not claim that every raw Claude error block is exposed as a MonitorMyGEO report control.
Use the measurement framework for denominator decisions. Next, confirm the measured provider surfaces and review the validity of one partially grounded observation before comparing its brand mentions with completed runs.
Fact-checked: 17 October 2026. Examples are illustrative; no customer results are reported.