Treat unknown or unsupported MCP properties as warnings instead of errors

[jmservera]

Is your feature request related to a problem? Please describe.
In the current preview version with MCP support, the toolkit fails when it encounters unsupported properties. While this behavior is documented for certain fields such as min/max, it becomes impractical in larger projects, where these validations can generate thousands of errors:

Additionally, several standard JSON Schema properties (e.g., title) are not currently supported, and many developers also include custom metadata in their MCP schemas. These are valid design practices but currently cause packaging to fail due to the strict validation.

Describe the solution you'd like
Treat unsupported or unknown MCP properties as warnings instead of errors. This would allow developers to successfully build and package their MCP plugins while still being clearly informed that those properties are ignored by Copilot.

Describe alternatives you've considered
The only current workaround is to manually edit the ai-plugin.json file. For larger schemas, we are considering adding a preprocessing script to strip unsupported fields before packaging, but this is error‑prone and adds unnecessary complexity to the workflow.

[m365-agent-toolkit-assistant]

👋 Hi @jmservera,

Thank you for reporting this issue! We want to let you know that:

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✨ This is an AI-generated initial response
🤖 AI-Generated Preliminary Analysis:

No directly matching issue found, but your request is aligned with common feedback for Microsoft 365 Agents Toolkit MCP plugin packaging.

Current Behavior:
The toolkit enforces strict validation—unknown or unsupported properties (such as custom metadata, title, or standard JSON schema fields) in your MCP agent manifest (ai-plugin.json) result in packaging errors, which is problematic for large schemas and standard design practices.

Workarounds:

• Manual Schema Cleanup: Strip unsupported fields before packaging (error-prone, especially for large files).
• Preprocessing Script: Automate schema clean-up, but this adds complexity.

Next Steps / Recommendations:

• Feature Request Tracking: There’s no public toolkit issue directly tracking this request yet, but similar strict validation topics arise. Consider filing or upvoting an issue here.
• Documentation: Stay updated with Toolkit MCP plugin docs.

Summary:
Apologies—currently, strict errors are default, so your workaround is necessary. Treating unknown/unsupported properties as warnings would be a useful enhancement for the developer workflow.

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Note: This is an automated first response generated by AI. A human team member will review your issue and provide a more detailed response soon. We appreciate your patience!

[sebastienlevert]

@jmservera, fully agree. We are working on a new way of representing the MCP tools schema that will solve this issue. @summzhan can share the latest, but it will solve these things massively as we 100% recognize this being a blocker.