docs(upstreammcp): add Upstream connector documentation

[ravibits]

Adds developer docs for the Upstream MCP connector — 46 tools covering inbox/email management (list/read/search threads, compose/reply, labels, channels, rules, inbox splits, org members, comments).

Related: scalekit-inc/tool-agent#390 (connector PR)

Stub disclosure

• _setup-upstreammcp.mdx has Bearer-auth setup steps auto-generated (3 steps: get bearer token / Personal Access Token, create connection, create connected account with Bearer Token field). Still needs:
  • Screenshots (replace {/* TODO: add screenshot ... */} markers)
  • Provider-specific navigation paths (replace {/* TODO: add provider-specific steps ... */} markers) — where in Upstream's dashboard/settings to generate a Personal Access Token
• _section-after-setup-upstreammcp-common-workflows.mdx is a cloned stub only (untouched) — needs workflow examples added.

Preview

https://deploy-preview-826--scalekit-starlight.netlify.app/agentkit/connectors/upstreammcp/

Test plan

• Open the preview link and verify the page renders.
• Tool list shows 46 tools.
• Replace {/* TODO: add screenshot ... */} markers in _setup-upstreammcp.mdx.
• Review the setup steps for connector-specific accuracy.

[coderabbitai]

Important

Review skipped

Draft detected.

Please check the settings in the CodeRabbit UI or the .coderabbit.yaml file in this repository. To trigger a single review, invoke the @coderabbitai review command.

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: ASSERTIVE

Plan: Pro

Run ID: f69e679f-1a96-4918-92ad-cbcd3faa5a12

You can disable this status message by setting the reviews.review_status to false in the CodeRabbit configuration file.

Use the checkbox below for a quick retry:

• 🔍 Trigger review

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch connector-docs/upstreammcp

• 🛠️ fix frontmatter
• 🛠️ fix internal links

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands.}

[netlify]

✅ Deploy Preview for scalekit-starlight ready!

Name	Link
🔨 Latest commit	fe58e4a
🔍 Latest deploy log	https://app.netlify.com/projects/scalekit-starlight/deploys/6a465b82f9e83e0008f8f0f7
😎 Deploy Preview	https://deploy-preview-826--scalekit-starlight.netlify.app
📱 Preview on mobile	Toggle QR Code... Use your smartphone camera to open QR code link.
Lighthouse	1 paths audited Performance: 56 (🟢 up 18 from production) Accessibility: 98 (no change from production) Best Practices: 92 (no change from production) SEO: 92 (no change from production) PWA: - View the detailed breakdown and full score reports
🤖 Make changes	Run an agent on this branch

---

To edit notification comments on pull requests, go to your Netlify project configuration.