Declarative Copilot agent reloads and starts a new chat session when inserting data into Excel

This behavior cannot be confirmed as expected or as a defect from the available information, and no Excel-specific workaround for declarative agents is documented in the provided context.

However, there are some relevant limitations and behaviors to be aware of when working with agents and Copilot experiences:

1. Session behavior and caching
   • Microsoft 365 Copilot can cache answers and behavior within a session. When testing agents in Copilot Studio, a new test session is sometimes required to reset state. This indicates that session handling and state transitions can be non-trivial and may differ between environments (Copilot Studio test panel vs. Microsoft 365 Copilot vs. Teams).
   • The documentation explicitly notes that “results you see at runtime in Microsoft 365 Copilot might be different from what you see in the test panel of Copilot Studio and in Microsoft Teams,” which implies that runtime behavior (including session continuity) can differ from expectations formed during testing.
2. Known limitations for custom engine agents
   While the issue described is about a declarative agent in Excel, the known issues for custom engine agents in Microsoft 365 Copilot show that:
   • Conversation context is limited: custom engine agents cannot access Copilot conversation history that occurred before the user accesses the agent via @mention.
   • Messages in Microsoft 365 Copilot are immutable and the updateActivity API is not supported.
   • There are also app-specific limitations: custom engine agents are not supported in Outlook, Word, Excel, PowerPoint, and Microsoft Edge.
   These points highlight that:
   • Conversation continuity and context handling are constrained for some agent types.
   • There are explicit app-scope limitations for custom engine agents in Excel and other Microsoft 365 apps.
3. Declarative agent manifest and conversation starters
   Declarative agents support configuration such as conversation_starters in the manifest, which helps guide users at the beginning of a conversation but does not control session lifetime or reload behavior. There is no manifest property in the provided schema that controls whether a session is reset when actions (such as writing to Excel) occur.
4. Workarounds and next steps
   From the provided context, no direct workaround is documented to prevent a declarative agent session from reloading when interacting with Excel. Given the known limitations and differences between environments:
   • Treat this as a potential product issue rather than something that can be fixed via manifest configuration.
   • Capture clear repro steps (as already outlined) and environment details (Excel client type, platform, tenant) and escalate through official Microsoft support channels or the appropriate product feedback path for Microsoft 365 Copilot/Excel.
   • When possible, design workflows so that each critical step is self-contained, anticipating that context might be lost, until the behavior is clarified or fixed by the product team.

References:

• Extend Microsoft 365 Copilot with agents
• Known issues
• Declarative agent schema 1.0 for Microsoft 365 Copilot
• Microsoft Excel experiences