primitive.dev
Description
Email infrastructure for AI agents — send, receive, search, and manage email over a clean HTTP API. Connect verified domains, route inbound mail, set up webhooks, and automate email workflows. Authenticate with a Primitive API key or via OAuth.
What our measurements say
primitive.dev is a remote MCP server published at primitive.dev. It has been probed 6 times since 9/10/2026. It answered in 6 of them (100.0%), a near-uninterrupted record. Median response time is 1,101 ms, a delay an agent will notice. It exposes a broad tool surface of 30 tools. On the protocol side it still runs 2025-11-25 and has not moved to the newer spec.
Agent readability score
Can an LLM agent pick the right tool here — names, descriptions and parameter clarity are assessed.
Agent readability score
Strengths
- Proactive workflow instructions (e.g., 'Call this BEFORE...')
- Clear distinction between simulation (sendEmailDemo) and real actions
- Detailed documentation of constraints and rate limits
- Logical and intuitive tool naming conventions
Weaknesses
- Generic 'requestBody' parameter names provide no structural hints in the summary
- Functional overlap between listEmails and searchEmails
- Subtle distinction between getThread and getConversation may require extra agent reasoning
listEmails— Significant parameter overlap with searchEmails might cause selection ambiguity.getThread— Potential confusion with getConversation regarding the optimal way to retrieve chat history.addDomain— Uses generic 'requestBody' which lacks field-level hints in the tool description.
Verdict
Event narrative
Risk: medium
- 2026-09-10T21:16:35.016Z — era changed from 'auth-gated' to 'legacy' · indicates system migration to legacy infrastructure
- 2026-09-11T07:35:54.413Z — complianceScore improved from null to 100 · confirms full regulatory compliance after era transition
Advice
Schema compliance
tools/list structure, inputSchema validity, and a functional smoke test — the components of the 0-100 score.
- tools/list schema valid
- inputSchema is valid JSON Schema
- Smoke test not run this round
- Cold-start: cold 264ms → warm 251ms (penalty 13ms)
Availability history
Event log
Derived by comparing consecutive probes — changes in era, protocol version, build and reachability.
- Server build: — → 0.1.0
- Supported versions: — → 2025-11-25
- Era changed: Auth-gated → Legacy
- Added to watch — era: Auth-gated
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