Microsoft Advertising MCP server returns empty tool list after successful OAuth (Claude, ChatGPT) — possible protected-resource metadata issue

Stefan Georgescu 0 Reputation points
2026-09-14T15:54:52.18+00:00

The Microsoft Advertising MCP server authenticates successfully but exposes no tools in any MCP client I've tested. Setup followed the official guide at learn.microsoft.com/en-us/advertising/guides/mcp-setup?view=bingads-13.

Environment

  • Endpoint: https://partner.api.bingads.microsoft.com/ext/mcp/vnext?toolSetNames=OpenBeta
  • Entra app registration: multitenant + personal Microsoft accounts, public-client redirect URIs, no client secret
  • Signed-in user: Super Admin on the Microsoft Advertising customer, with ad account access confirmed in the UI

Behaviour

ClientResultClaude (web)OAuth completes, connector shows connected, tool list empty----------------Claude (web)OAuth completes, connector shows connected, tool list empty----------------Claude (web)OAuth completes, connector shows connected, tool list emptyClaude (desktop app)IdenticalClaude, URL without ?toolSetNames=OpenBetaIdenticalChatGPT (developer mode, auto-discovery)OAuth completes, then "There was a problem connecting" on redirect backChatGPT, manual OAuth fields per setup guideIdentical errorNo error is surfaced in Claude — the connector simply reports no tools available.

Possible cause

The protected-resource metadata at https://partner.api.bingads.microsoft.com/ext/mcp/vnext/.well-known/oauth-protected-resource returns:

json

"resource": "https://partner.api.bingads.microsoft.com/ext/mcp/vnext",
"authorization_servers": [
  "https://login.microsoftonline.com/client/v2.0",
  "https://accounts.google.com"
]

Two things look wrong:

  1. The first advertised authorization server is login.microsoftonline.com/**client**/v2.0, whereas the setup guide documents login.microsoftonline.com/**common**/oauth2/v2.0. Is client intended, or a placeholder that wasn't substituted?
  2. https://accounts.google.com is listed as an authorization server for a Microsoft Advertising endpoint.

Could you confirm whether this metadata is correct, and whether the MCP server is currently expected to work with Claude and ChatGPT?

Microsoft Advertising API
Microsoft Advertising API

A Microsoft API that provides programmatic access to Microsoft Advertising to manage large campaigns or to integrate your marketing with other in-house systems.

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Answer recommended by moderator
MS Advertising - Marvin 160 Reputation points Microsoft External Staff Moderator
2026-09-21T16:42:05.3933333+00:00

Hello,

Thank you for using our Microsoft Advertising Learn Q&A Platform!

Troubleshooting Microsoft Advertising MCP: Connector Has No Tools Available

Resolution

This issue has been confirmed as resolved.

The MCP connector began loading the available tools and returning Microsoft Advertising data after a Microsoft-identity user was added to the advertising account and used to reconnect the connector.

Confirmed Cause

The Microsoft Advertising account was originally registered using a Google identity. During the MCP connection process, the client attempted to authenticate through a Microsoft identity, resulting in the following identity mismatch error:

Error 126: IdentityTypeMismatch / GoogleAccountIsRequired

The issue was not caused by the Entra app registration, MCP server, or configured endpoint URL.

Verified Workaround

If your Microsoft Advertising account was registered using a Google identity and the MCP connector cannot load its tools, try the following:

  1. Add a user with a Microsoft identity to the Microsoft Advertising account.
  2. Grant that user access to the appropriate advertising account.
  3. Reconnect the MCP connector.
  4. Sign in using the newly added Microsoft-identity user.

After completing these steps, the MCP tools should load and begin returning advertising data. No changes to the Entra app registration or MCP endpoint URL should be necessary.

Additional Technical Note

The Google authorization server entry in the protected-resource metadata is intentional for accounts associated with Google identities and should not be treated as a configuration error.

Some MCP clients may not clearly display the underlying identity mismatch. For example, the issue may appear only as:

  • Connector has no tools available
  • Problem connecting

In this case, checking whether the Microsoft Advertising account was created using a Google identity may help identify the cause.

Recommendation

It would be helpful to include identity-selection guidance in the MCP setup documentation, particularly for advertisers whose Microsoft Advertising accounts were created using Google identities. A clearer identity-mismatch message during tool discovery could also make the issue easier to identify and prevent unnecessary changes to the Entra app registration or MCP endpoint.

I hope this resolution note helps you, who encounter the same behavior while setting up their Microsoft Advertising MCP connection.

Thank you @Stefan Georgescu for sharing your observation and fixes on the issue through in-depth analysis while we are working on this to be fixed.

Our support teams are pleased to engage in more in-depth discussions about your account through phone, chat, or email to offer review assistance, please see our support page to reach out!

I trust that the details shared here will partially address your inquiry. Should you have any further questions, feel free to contact our support.

Kind regards, 

Marvin | Microsoft Advertising Support Specialist | 800-518-5689 

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  1. MS Advertising - Marvin 160 Reputation points Microsoft External Staff Moderator
    2026-09-14T21:28:28.98+00:00

    Hello @Stefan Georgescu ,

    Thank you for using our Microsoft Advertising Learn Q&A Platform!

    Thank you for the detailed report and for testing the connection across multiple MCP clients.

    Based on the current Microsoft Advertising MCP documentation, both Claude and ChatGPT are listed as supported clients. The documented configurations use the Microsoft Entra common OAuth 2.0 endpoints and the https://ads.microsoft.com/msads.manage scope. The documentation also confirms that the server should expose read-only tools such as GetAccounts, GetCampaigns, GetAdGroups, GetAds, GetKeywords, GetAssetGroups, and GetAudienceAssociations.

    Since authentication completes but tool discovery returns an empty list across multiple clients, the issue does not appear to be explained by account permissions alone. The authorization-server values you found in the protected-resource metadata also do not align with the OAuth endpoints documented in the setup guide. However, the available public documentation does not confirm whether client and the Google authorization-server entry are intentional.

    One configuration difference is worth checking: the current guide specifies the base MCP endpoint without the toolSetNames=OpenBeta query parameter for ChatGPT, while Claude uses the endpoint with that parameter. Since you have already tested both endpoint formats, this further suggests that the behavior may require review by our Internal Review Team. I’ve sent you a private message requesting additional information to forward a review to them for this case.

    Our support teams are pleased to engage in more in-depth discussions about your account through phone, chat, or email to offer review assistance, please see our support page to reach out!

    I trust that the details shared here will partially address your inquiry. Should you have any further questions, feel free to contact our support. 

             Note: Please see troubleshooting guide under the comment section in this answer post.

     

    Kind regards, 

    Marvin | Microsoft Advertising Support Specialist | 800-518-5689 

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