[BUG] Claude for PowerPoint: MCP connector tools are not loaded into Claude's tool list at session start; only become available after refresh_mcp_connectors runs

Status Open

Maintainer reply None cached

Activity 4 comments · opened May 13, 2026

Summary

MCP-connector tools are not available to Claude on the first turn of a new Claude for PowerPoint session, even when the connector is connected and enabled. Claude ignores the MCP server entirely and falls back to built-in tools.

The tools only become visible after the user manually types "refresh Acme MCP tools", which triggers refresh_mcp_connectors. This is an undocumented workaround users shouldn't need to know.

Environment

Product: Claude for PowerPoint add-in
Host: PowerPoint on Windows (Microsoft 365 desktop)
Model: Claude Opus 4.7 / Sonnet 4.6 (both affected)
Plan: Enterprise
MCP server: Custom .NET 10 server, Streamable HTTP, tools.listChanged = true

Steps to Reproduce

Register and enable a custom MCP connector ("Acme MCP") in the Claude for PowerPoint connector settings.
Close and reopen the Claude task pane to start a fresh session.
Send a request that matches a tool on the MCP server (e.g. "update all links").
Observe that Claude ignores the MCP connector and uses only built-in tools, then fails.
Send "refresh Acme MCP tools" — Claude calls refresh_mcp_connectors and confirms "Acme MCP is connected."
Re-send the original request — Claude now correctly calls the MCP tool and completes the task.

Expected Behaviour

MCP connector tools should be fetched and merged into Claude's tool list before the first user message is processed, so they are available on turn 1 without any manual refresh.

Actual Behaviour

MCP tools are lazy-loaded and absent on turn 1. Claude ignores the connector and fails to complete requests it could handle, requiring users to manually trigger a refresh first.

Proposed Fix

At session start (or when a connector is toggled on), call tools/list before the first user message is sent. If the server declares tools.listChanged = true, also register a notifications/tools/list_changed handler. As a minimum, run refresh_mcp_connectors implicitly at session start.

Related Issues

#13646 — MCP tool list not refreshed on notifications/tools/list_changed
#27193 — "Tool names must be unique" error on first message

Contact

Reporter: Larry — happy to provide server logs or a screen recording on request.

View original on GitHub ↗

4 Comments

github-actions[bot] · 3 months ago

Found 3 possible duplicate issues:

This issue will be automatically closed as a duplicate in 3 days.

If your issue is a duplicate, please close it and 👍 the existing issue instead
To prevent auto-closure, add a comment or 👎 this comment

🤖 Generated with Claude Code

larrygfr · 3 months ago

Not a duplicate:

#49753 — intermittent SDK/CLI race; mine is 100% reproducible and not in the CLI.
#35899 — unattended scheduled tasks; mine is an interactive task pane.
#51138 — connector never works; mine works fine after refresh_mcp_connectors.

edwinsjr · 3 months ago

I can repro for my own MCP connector. I would hate to add "Refresh the tool page until tools show up" to my instructions.

Quertie · 3 months ago

Same here. Ideally Claude should proactively start using MCP tools so that the MCP server itself is as transparent as possible to the user (while of course Claude remaining explicit about its tool usage)