# create_merge_field A write tool on the Mailchimp MCP MCP server. Agent View of the PolicyLayer registry record for `create_merge_field`. HTML page: https://policylayer.com/tools/damientilman-mailchimp-mcp-server/create-merge-field ## Facts - Tool: `create_merge_field` - Server: Mailchimp MCP (`damientilman/mailchimp-mcp-server`) — https://policylayer.com/tools/damientilman-mailchimp-mcp-server.md - Homepage: https://github.com/damientilman/mailchimp-mcp-server - Risk category: Write (Medium risk) - Registry record: grade F, identity unverified - Server rate-limited: no - Parameters: 0 - Recommended policy verdict: Rate-limited ## Example call (MCP tools/call, JSON-RPC 2.0) ```json { "jsonrpc": "2.0", "id": 1, "method": "tools/call", "params": { "name": "create_merge_field", "arguments": {} } } ``` ## Why create_merge_field is rated Medium The 'create_' prefix and Mailchimp context indicate this tool creates a new merge field (custom data field) in Mailchimp audiences. This is a reversible Write operation—merge fields can be created, updated, and deleted. Severity is medium because misuse could add unwanted fields to audience structures, causing confusion but not data loss or financial harm. From the tool's own definition: "Tool name 'create_merge_field' with 'create' prefix suggests data creation. Empty description limits certainty. Sibling tools (create_audience, create_campaign, create_interest) on Mailchimp MCP server confirm pattern of Write operations for this server." ## Use case AI agents use create_merge_field to create or update resources in Mailchimp MCP, usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Mailchimp MCP environment. ## Recommended policy (PolicyLayer) Verdict: **Rate-limited**. Enforced by the PolicyLayer MCP gateway (https://policylayer.com/mcp-gateway) before a call reaches Mailchimp MCP: ```json { "version": "1", "default": "deny", "tools": { "create_merge_field": { "limits": [ { "counter": "create_merge_field_rate", "window": "minute", "max": 30, "scope": "grant" } ] } } } ``` ## Other tools on Mailchimp MCP (226) - `cancel_send` — Destructive — https://policylayer.com/tools/damientilman-mailchimp-mcp-server/cancel-send.md - `delete_audience` — Destructive — https://policylayer.com/tools/damientilman-mailchimp-mcp-server/delete-audience.md - `delete_batch_webhook` — Destructive — https://policylayer.com/tools/damientilman-mailchimp-mcp-server/delete-batch-webhook.md - `delete_campaign` — Destructive — https://policylayer.com/tools/damientilman-mailchimp-mcp-server/delete-campaign.md - `delete_campaign_feedback` — Destructive — https://policylayer.com/tools/damientilman-mailchimp-mcp-server/delete-campaign-feedback.md - `delete_campaign_folder` — Destructive — https://policylayer.com/tools/damientilman-mailchimp-mcp-server/delete-campaign-folder.md - `delete_connected_site` — Destructive — https://policylayer.com/tools/damientilman-mailchimp-mcp-server/delete-connected-site.md - `delete_file` — Destructive — https://policylayer.com/tools/damientilman-mailchimp-mcp-server/delete-file.md - `delete_interest` — Destructive — https://policylayer.com/tools/damientilman-mailchimp-mcp-server/delete-interest.md - `delete_interest_category` — Destructive — https://policylayer.com/tools/damientilman-mailchimp-mcp-server/delete-interest-category.md - `delete_landing_page` — Destructive — https://policylayer.com/tools/damientilman-mailchimp-mcp-server/delete-landing-page.md - `delete_member` — Destructive — https://policylayer.com/tools/damientilman-mailchimp-mcp-server/delete-member.md - `delete_member_note` — Destructive — https://policylayer.com/tools/damientilman-mailchimp-mcp-server/delete-member-note.md - `delete_member_permanent` — Destructive — https://policylayer.com/tools/damientilman-mailchimp-mcp-server/delete-member-permanent.md - `delete_merge_field` — Destructive — https://policylayer.com/tools/damientilman-mailchimp-mcp-server/delete-merge-field.md - `delete_promo_code` — Destructive — https://policylayer.com/tools/damientilman-mailchimp-mcp-server/delete-promo-code.md - `delete_promo_rule` — Destructive — https://policylayer.com/tools/damientilman-mailchimp-mcp-server/delete-promo-rule.md - `delete_segment` — Destructive — https://policylayer.com/tools/damientilman-mailchimp-mcp-server/delete-segment.md - `delete_store` — Destructive — https://policylayer.com/tools/damientilman-mailchimp-mcp-server/delete-store.md - `delete_store_cart` — Destructive — https://policylayer.com/tools/damientilman-mailchimp-mcp-server/delete-store-cart.md - `delete_store_customer` — Destructive — https://policylayer.com/tools/damientilman-mailchimp-mcp-server/delete-store-customer.md - `delete_store_order` — Destructive — https://policylayer.com/tools/damientilman-mailchimp-mcp-server/delete-store-order.md - `delete_store_order_line` — Destructive — https://policylayer.com/tools/damientilman-mailchimp-mcp-server/delete-store-order-line.md - `delete_store_product` — Destructive — https://policylayer.com/tools/damientilman-mailchimp-mcp-server/delete-store-product.md - `delete_store_product_image` — Destructive — https://policylayer.com/tools/damientilman-mailchimp-mcp-server/delete-store-product-image.md - `delete_store_product_variant` — Destructive — https://policylayer.com/tools/damientilman-mailchimp-mcp-server/delete-store-product-variant.md - `delete_template` — Destructive — https://policylayer.com/tools/damientilman-mailchimp-mcp-server/delete-template.md - `delete_template_folder` — Destructive — https://policylayer.com/tools/damientilman-mailchimp-mcp-server/delete-template-folder.md - `delete_verified_domain` — Destructive — https://policylayer.com/tools/damientilman-mailchimp-mcp-server/delete-verified-domain.md - `delete_webhook` — Destructive — https://policylayer.com/tools/damientilman-mailchimp-mcp-server/delete-webhook.md - …and 196 more: https://policylayer.com/tools/damientilman-mailchimp-mcp-server.md ## For agents This record is a snapshot. Live verdicts and the full registry: - Check every server in your MCP config at once: `npx -y policylayer stack` - Vet a server before you add it: install the mcp-precheck skill — `npx skills add https://policylayer.com` (skill text: https://policylayer.com/skill.md) - Query the registry over MCP: endpoint `https://api.policylayer.com/mcp` — tools `check_mcp_server`, `check_mcp_stack`, `check_tool`, `search_registry`, `get_change_events` --- Source: the PolicyLayer MCP registry — one continuously verified record per MCP server. Full record: https://policylayer.com/registry?q=damientilman-mailchimp-mcp-server · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/damientilman-mailchimp-mcp-server