Google Contacts: Add/remove group members — MCP tool

Google Contacts MCP tool: Adds and removes contacts to/from a contact group in a single call.

Technical name: modify_group_members

What task it solves

I want to change which contacts carry a label.

Adds and/or removes contacts (people/c...) to/from a group in one call.

When to use it

Use it to label or unlabel contacts — including starring via contactGroups/starred. Removing a member does NOT delete the contact.

What to provide

• resource_name — required. contactGroups/....
• add — optional. Contacts to add.
• remove — optional. Contacts to remove.

At least one of add/remove is required; the API caps add+remove at 1000 names combined.

What it returns

Only problems: notFoundResourceNames and canNotRemoveLastContactGroupResourceNames. An empty object means full success.

What changes in Google Contacts

The listed contacts gain or lose the label; the contacts themselves are untouched.

Example request

Add these three contacts to "Conference 2026" and remove people/c42 from it.

Errors and limitations

Re-running the same call converges (already-member / already-removed are not errors). Membership in a contact's last group cannot always be removed (see canNotRemoveLastContactGroupResourceNames). Access also depends on token permissions, quotas, and upstream API limits.

Related MCP tools

• Get a contact group — get_contact_group
• Create a contact group — create_contact_group
• Delete a contact — delete_contact

Technical details

• Impact: destructive operation
• Group: Contact groups
• Description source: modify_group_members registration in src/tools/groups.ts
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