github plugin: enable the Actions toolset so Claude can check CI with fine-grained tokens

Problem

The github plugin connects to https://api.githubcopilot.com/mcp/ without choosing toolsets, so it only gets GitHub's default toolsets. actions is not one of them.

With a classic token, Claude can still see CI status through pull_request_read (get_check_runs), but not workflow logs. With a fine-grained personal access token, it cannot see CI status at all: fine-grained tokens have no "Checks" permission, so get_check_runs returns 403, and without the Actions toolset there is no other way to read workflow runs. Claude then cannot check whether CI passed before merging a pull request.

Proposal

Add actions to the default toolsets with the X-MCP-Toolsets header (documented here) in external_plugins/github/.mcp.json:

     "headers": {
-      "Authorization": "Bearer ${GITHUB_PERSONAL_ACCESS_TOKEN}"
+      "Authorization": "Bearer ${GITHUB_PERSONAL_ACCESS_TOKEN}",
+      "X-MCP-Toolsets": "default,actions"
     }

default keeps every tool users have today. I checked tools/list against the remote server on 2026-10-22:

actions_run_trigger can start, re-run and cancel workflows. It is gated by the token's permissions like every other write tool the plugin already exposes: with "Actions: Read-only", the tool is listed but its calls fail.

Related

• #3296 proposed a fixed toolset list that included actions. It was closed automatically as an external PR. That list would also have removed toolsets users rely on today; this proposal only adds one.