mcp-registry/io.github.spruikco/send16-mcp · v0.5.15
Also listed as glama/spruikco/send16-mcp
As of 2026-10-20 05:05 UTC, the Spruikco Send16 MCP server is up with a Glimind reliability score of 91/100 (grade A). Over the last 30 days it answered 99.9% of Glimind's liveness checks. It had 7 outages in 90 days, with a median recovery of 1 minutes.
Email for AI agents: send mail, manage contacts, automations & webhooks. Zero-DNS first send.
Claude Code
claude mcp add --transport http spruikco-send16-mcp-server https://mcp.send16.com/mcp
Claude Desktop · Windsurf · Cline (mcpServers JSON)
{
"mcpServers": {
"spruikco-send16-mcp-server": {
"type": "http",
"url": "https://mcp.send16.com/mcp"
}
}
}
Third-party server, listed as discovered. Review its source before installing.
82 of 82 tool(s) carry no readOnlyHint/destructiveHint annotations.
Annotate read-only tools with {"readOnlyHint": true}. Agents and gateways can then run them without a confirmation prompt, and route around destructive ones. How to fix →
82 tools on one server. Tool-selection accuracy drops as the menu grows, and some clients (e.g. Cursor) cap the number of active tools.
Group tools by task into smaller servers or toolsets, and merge near-duplicates behind one tool with a mode parameter. How to fix →
27 tool(s) look like they change state (create/send/delete/pay…) but declare no destructiveHint.
Set annotations {"readOnlyHint": false, "destructiveHint": true|false, "idempotentHint": …}. Clients use these to ask the user before a side effect and to auto-approve safe reads. How to fix →
38 parameter(s) across 13 tool(s) have no description.
Add a "description" to each parameter with its format and an example ("ISO 8601 date, e.g. 2026-10-17"). This is the commonest cause of wrong arguments on the first call. How to fix →
1 tool(s) have descriptions under 20 characters.
Say when to use the tool and what it returns, not just its name restated ("Get weather" → "Current weather for a city: temperature, conditions, wind. Use for 'now', not forecasts."). How to fix →
Loading this server's tool list costs an agent ~14,802 tokens before any work — more than 90% of MCP servers.
Split rarely-used tools into a separate server or a toolset the client can enable, or expose one "search tools" entry point. Many agents load every connected server's tools into every request. How to fix →
No tool declares an outputSchema.
Declare outputSchema and return structuredContent (MCP 2025-06-18+). Agents can then parse results without guessing, and chain tools reliably. How to fix →
In the last 30 days: 0 tool(s) removed and 13 schema change(s).
Add new tools or optional parameters instead of renaming or removing; deprecate first (say so in the description) and remove later. Agents cache tool contracts. How to fix →
Paste-ready definitions with the problems above fixed. Changes marked verify need a human look. 13 tool(s) still need parameter descriptions written by someone who knows the API. All of them as JSON: /v1/readiness/mcp-registry%2Fio.github.spruikco%2Fsend16-mcp/fixes
{
"name": "add_contacts_to_audience",
"description": "Add contacts (by ID) to an audience.",
"inputSchema": {
"type": "object",
"$schema": "http://json-schema.org/draft-07/schema#",
"required": [
"audienceId",
"contactIds"
],
"properties": {
"apiKey": {
"type": "string",
"description": "Send16 API key (overrides SEND16_API_KEY env var)"
},
"audienceId": {
"type": "string",
"description": "Audience ID"
},
"contactIds": {
"type": "array",
"items": {
"type": "string"
},
"maxItems": 1000,
"minItems": 1,
"description": "Contact IDs to add"
}
}
},
"annotations": {
"readOnlyHint": false,
"destructiveHint": false,
"idempotentHint": false
}
}{
"name": "add_convo_note",
"description": "Add a private internal note on a conversation. Notes are visible only to workspace members.",
"inputSchema": {
"type": "object",
"$schema": "http://json-schema.org/draft-07/schema#",
"required": [
"convoId",
"body"
],
"properties": {
"body": {
"type": "string",
"minLength": 1,
"description": "Note body (markdown supported)"
},
"apiKey": {
"type": "string",
"description": "Send16 API key (overrides SEND16_API_KEY env var)"
},
"convoId": {
"type": "string",
"description": "Conversation ID"
}
}
},
"annotations": {
"readOnlyHint": false,
"destructiveHint": false,
"idempotentHint": false
}
}{
"name": "add_domain",
"description": "Register a new sending domain. Returns the DNS records the user must add to their DNS provider, after which they should call check_domain_health to verify.",
"inputSchema": {
"type": "object",
"$schema": "http://json-schema.org/draft-07/schema#",
"required": [
"domain"
],
"properties": {
"apiKey": {
"type": "string",
"description": "Send16 API key (overrides SEND16_API_KEY env var)"
},
"domain": {
"type": "string",
"maxLength": 255,
"minLength": 3,
"description": "FQDN to register (e.g. 'mail.example.com')"
}
}
},
"annotations": {
"readOnlyHint": false,
"destructiveHint": false,
"idempotentHint": false
}
}Get an email or webhook when this server's readiness drops by 10+ points, tool-poisoning text appears, or a tool breaks:
curl -X POST https://glimind.com/v1/subscriptions -H 'content-type: application/json' -d '{"tools":["mcp-registry/io.github.spruikco/send16-mcp"],"email":"[email protected]"}'Agents: watch_tool({"toolId": "mcp-registry/io.github.spruikco/send16-mcp"}) over MCP.
send_email ~612 tokenscreate_campaign ~541 tokenssave_template ~506 tokensupdate_campaign ~475 tokenssend_broadcast ~453 tokensStatic checks of the advertised tools/list (schema, descriptions, annotations, tool-poisoning patterns, names, size) plus observed protocol, uptime, latency and contract changes. Read-only: no tool is ever called. Weights: schema 15, docs 20, safety 15, efficiency 15, compatibility 15, protocol 5, reliability 10, stability 5. Token counts are estimates (~3.6 characters per token).
Operator? Fix these, then re-check live. Embed the readiness badge:
[](https://glimind.com/server/mcp-registry%2Fio.github.spruikco%2Fsend16-mcp?ref=badge)
<a href="https://glimind.com/server/mcp-registry%2Fio.github.spruikco%2Fsend16-mcp?ref=badge"><img src="https://glimind.com/v1/readiness/badge/mcp-registry%2Fio.github.spruikco%2Fsend16-mcp.svg" alt="MCP agent-readiness"></a>
.. image:: https://glimind.com/v1/readiness/badge/mcp-registry%2Fio.github.spruikco%2Fsend16-mcp.svg :target: https://glimind.com/server/mcp-registry%2Fio.github.spruikco%2Fsend16-mcp?ref=badge :alt: MCP agent-readiness
Glimind records every version of this server's tool definitions in a signed, append-only transparency log. Current manifest sha256:1dbd59bf0dcc79f0…, first seen 2026-10-17, included at leaf 14988 of 30,890. Version history · verify what your client received.
Compare: most reliable communication servers · most reliable email servers · most reliable security servers · most reliable automation servers · most reliable database servers
Glimind tells agents whether a server is up right now and how to call it, then fails over to a live alternative when it isn't.
Claude Code
claude mcp add --transport http glimind https://glimind.com/mcp
Claude Desktop · Windsurf · Cline (mcpServers JSON)
{
"mcpServers": {
"glimind": {
"type": "http",
"url": "https://glimind.com/mcp"
}
}
}
As of 2026-10-20 05:05 UTC, the Spruikco Send16 MCP server is up with a Glimind reliability score of 91/100 (grade A). Over the last 30 days it answered 99.9% of Glimind's liveness checks. It had 7 outages in 90 days, with a median recovery of 1 minutes.
Spruikco Send16 MCP server advertises 82 tools, including activate_automation, add_contacts_to_audience, add_convo_note, add_domain, add_suppression.
Point your MCP client at this streamable-http endpoint: https://mcp.send16.com/mcp
Glimind scanned all 82 tool definitions for tool-poisoning patterns — hidden or invisible characters, instructions that override the model, concealment from the user, requests to read credential or MCP config files, conversation exfiltration and cross-tool shadowing — and found none. This checks what the server tells the model, not what its code does; review the source before granting access to sensitive data.
Status page: 90-day uptime, every outage and how long it lasted.
Claim this listing to get the Verified operator marker, a remediation checklist and owner analytics, or embed the live badge from any of the tool pages above. Maintainers: alerts, deploy attestation and monthly reports.
Status is an automated estimate from Glimind's liveness checks (handshake and tool listing only; no tool is ever called) and may lag or differ from your network. Glimind is not affiliated with this server or its operator. Operator? Request a correction or opt out at https://glimind.com/opt-out.