Devin MCP write scopes by default: Sume keeps write opt-in

Devin's September 25 release notes say Microsoft 365 MCP connections now request all read/write permissions that do not need admin approval by default. That is Microsoft 365 only. Sume's hosted MCP works the other way: mcp:read is required and mcp:write is opt-in, and the consent page has the Write toggle off by default.

Vendor facts are from the Devin release notes; Sume facts are from MCP OAuth and MCP tools and gates, read 2026-10-01.

What did Devin change?

The notes say the change lets Devin send mail, create events and post in Teams without reconnecting. The wording covers Microsoft 365 MCP connections; the notes do not describe other servers as changing.

What scopes does Sume request?

The docs list two supported scopes. Granting write always includes read.

What happens if the user leaves Write off?

The session only sees read-only tools, and a mutating call returns insufficient_scope. Job reads such as jobs_status still work. A session that needs to submit a paid generation has to be reconnected with Write granted, or use an API key. See Claude Code 403 insufficient scope for the re-auth flow.

Does Write mean the agent can spend freely?

No scope grants spend on its own. Paid and write tools require an idempotency_key, and dry_run=true previews admission and cost without submitting. max_spend_usd is enforced only when you send it.

What should I check when I connect an MCP in Devin?

Read the permission list on the consent screen before approving, and grant Write only when the agent has a task that needs it. The same habit applies to any server whose default scopes change between releases; see Zed MCP OAuth scopes.