Gmail Calendar — the complete, unedited output of the deterministic mcptrustchecker engine v1.13.0, scanned . Every finding, capability tag and score component below is exactly what the engine produced — no AI, no post-processing.
{
"tool": {
"name": "mcptrustchecker",
"version": "1.13.0",
"methodologyVersion": "mcptrustchecker-1.13"
},
"target": {
"id": "gmail-calendar-mcp",
"source": {
"kind": "package",
"origin": "gmail-calendar-mcp"
},
"server": {
"name": "gmail-calendar-mcp"
}
},
"grade": "A",
"score": {
"score": 95,
"threatScore": 100,
"grade": "A",
"band": "A",
"categorySubtotals": {
"injection": 0,
"exfiltration": 0,
"permissions": 0,
"supply-chain": 0,
"network": 0,
"hygiene": 0
},
"vector": [
{
"kind": "client",
"term": "capability-exposure",
"level": "moderate",
"label": "capability blast radius (moderate) — client exposure if the model is manipulated",
"appliedPenalty": 3
},
{
"kind": "client",
"term": "verification-discount",
"level": "none",
"label": "publisher verification (unlinked) — no provenance/repo link, but the shipped source was fully read",
"appliedPenalty": 2
},
{
"kind": "client",
"term": "coverage-honesty",
"level": "source",
"label": "inspection depth (source) — how much of the target the scan could see",
"appliedPenalty": 0
}
],
"gatesFired": [],
"methodologyVersion": "mcptrustchecker-1.13"
},
"capability": {
"level": "moderate",
"reasons": [
"ingests untrusted external content (a prompt-injection entry point)",
"can send data / act on an external service"
],
"tags": [
"untrusted-input",
"external-sink"
]
},
"coverage": {
"level": "source",
"inputs": {
"toolSurface": true,
"implementationSource": true,
"packageMetadata": true,
"liveTransport": false
},
"caveats": [
"Tools were statically extracted from the published source (72 recovered), not enumerated from a running server. Tool-poisoning, Unicode-smuggling, capability and toxic-flow analysis ran on this inferred surface, but a mis-parsed registration could be missed or mis-attributed, so tool-derived findings are capped below “confirmed”. To grade the real runtime surface, scan the running server: --command \"npx -y <package>\"."
]
},
"findings": [
{
"ruleId": "MTC-FLOW-005",
"title": "Untrusted input can drive an external action",
"category": "exfiltration",
"severity": "medium",
"confidence": "strong",
"description": "Untrusted-input tools ([download_attachment]) co-exist with external-action tools ([send_email, forward_message]). A prompt injection could cause unwanted external actions, though no direct sensitive-data leak path was found.",
"remediation": "Require confirmation for state-changing/egress actions triggered after processing untrusted content.",
"location": {
"kind": "flow",
"name": "download_attachment → send_email"
},
"evidence": "untrusted [download_attachment] → sinks [send_email, forward_message]",
"owasp": "LLM06:2025 Excessive Agency",
"references": [],
"data": {
"untrusted": [
"download_attachment"
],
"sinks": [
"send_email",
"forward_message"
]
}
},
{
"ruleId": "MTC-SUP-011",
"title": "Package declares no source repository",
"category": "supply-chain",
"severity": "info",
"confidence": "strong",
"description": "\"gmail-calendar-mcp\" declares no repository URL, so its published artifact cannot be compared against reviewable source.",
"remediation": "Prefer packages that link to public, reviewable source.",
"location": {
"kind": "package",
"name": "gmail-calendar-mcp"
}
}
],
"toxicFlows": [
{
"id": "flow-1",
"severity": "medium",
"confidence": "strong",
"untrustedInput": [
"download_attachment"
],
"sensitiveSource": [],
"externalSink": [
"send_email",
"forward_message"
],
"selfContained": false,
"description": "Untrusted input can drive an external action even though no sensitive source is exposed."
}
],
"capabilities": [
{
"tool": "get_message_attachments",
"tags": [],
"reasons": {}
},
{
"tool": "download_attachment",
"tags": [
"untrusted-input"
],
"reasons": {
"untrusted-input": [
"keyword \"download\""
]
}
},
{
"tool": "batch_modify_messages",
"tags": [],
"reasons": {}
},
{
"tool": "batch_trash",
"tags": [],
"reasons": {}
},
{
"tool": "batch_untrash",
"tags": [],
"reasons": {}
},
{
"tool": "list_calendars",
"tags": [],
"reasons": {}
},
{
"tool": "get_calendar",
"tags": [],
"reasons": {}
},
{
"tool": "create_calendar",
"tags": [],
"reasons": {}
},
{
"tool": "update_calendar",
"tags": [],
"reasons": {}
},
{
"tool": "delete_calendar",
"tags": [],
"reasons": {}
},
{
"tool": "clear_calendar",
"tags": [],
"reasons": {}
},
{
"tool": "subscribe_calendar",
"tags": [],
"reasons": {}
},
{
"tool": "unsubscribe_calendar",
"tags": [],
"reasons": {}
},
{
"tool": "update_calendar_subscription",
"tags": [],
"reasons": {}
},
{
"tool": "list_events",
"tags": [],
"reasons": {}
},
{
"tool": "get_event",
"tags": [],
"reasons": {}
},
{
"tool": "create_event",
"tags": [],
"reasons": {}
},
{
"tool": "update_event",
"tags": [],
"reasons": {}
},
{
"tool": "delete_event",
"tags": [],
"reasons": {}
},
{
"tool": "quick_add_event",
"tags": [],
"reasons": {}
},
{
"tool": "move_event",
"tags": [],
"reasons": {}
},
{
"tool": "list_event_instances",
"tags": [],
"reasons": {}
},
{
"tool": "respond_to_event",
"tags": [],
"reasons": {}
},
{
"tool": "import_event",
"tags": [],
"reasons": {}
},
{
"tool": "get_freebusy",
"tags": [],
"reasons": {}
},
{
"tool": "list_settings",
"tags": [],
"reasons": {}
},
{
"tool": "get_setting",
"tags": [],
"reasons": {}
},
{
"tool": "get_colors",
"tags": [],
"reasons": {}
},
{
"tool": "list_acl",
"tags": [],
"reasons": {}
},
{
"tool": "share_calendar",
"tags": [],
"reasons": {}
},
{
"tool": "update_acl",
"tags": [],
"reasons": {}
},
{
"tool": "unshare_calendar",
"tags": [],
"reasons": {}
},
{
"tool": "create_draft",
"tags": [],
"reasons": {}
},
{
"tool": "list_drafts",
"tags": [],
"reasons": {}
},
{
"tool": "send_draft",
"tags": [],
"reasons": {}
},
{
"tool": "update_draft",
"tags": [],
"reasons": {}
},
{
"tool": "delete_draft",
"tags": [],
"reasons": {}
},
{
"tool": "list_filters",
"tags": [],
"reasons": {}
},
{
"tool": "create_filter",
"tags": [],
"reasons": {}
},
{
"tool": "delete_filter",
"tags": [],
"reasons": {}
},
{
"tool": "list_labels",
"tags": [],
"reasons": {}
},
{
"tool": "create_label",
"tags": [],
"reasons": {}
},
{
"tool": "update_label",
"tags": [],
"reasons": {}
},
{
"tool": "delete_label",
"tags": [],
"reasons": {}
},
{
"tool": "label_message",
"tags": [],
"reasons": {}
},
{
"tool": "unlabel_message",
"tags": [],
"reasons": {}
},
{
"tool": "label_thread",
"tags": [],
"reasons": {}
},
{
"tool": "unlabel_thread",
"tags": [],
"reasons": {}
},
{
"tool": "get_profile",
"tags": [],
"reasons": {}
},
{
"tool": "get_message",
"tags": [],
"reasons": {}
},
{
"tool": "search_messages",
"tags": [],
"reasons": {}
},
{
"tool": "search_threads",
"tags": [],
"reasons": {}
},
{
"tool": "get_thread",
"tags": [],
"reasons": {}
},
{
"tool": "send_email",
"tags": [
"external-sink"
],
"reasons": {
"external-sink": [
"keyword \"send_email\""
]
}
},
{
"tool": "reply_to_message",
"tags": [],
"reasons": {}
},
{
"tool": "forward_message",
"tags": [
"external-sink"
],
"reasons": {
"external-sink": [
"keyword \"forward_message\""
]
}
},
{
"tool": "get_signature",
"tags": [],
"reasons": {}
},
{
"tool": "update_signature",
"tags": [],
"reasons": {}
},
{
"tool": "get_vacation_responder",
"tags": [],
"reasons": {}
},
{
"tool": "set_vacation_responder",
"tags": [],
"reasons": {}
},
{
"tool": "mark_read",
"tags": [],
"reasons": {}
},
{
"tool": "mark_unread",
"tags": [],
"reasons": {}
},
{
"tool": "star",
"tags": [],
"reasons": {}
},
{
"tool": "unstar",
"tags": [],
"reasons": {}
},
{
"tool": "archive",
"tags": [],
"reasons": {}
},
{
"tool": "move_to_inbox",
"tags": [],
"reasons": {}
},
{
"tool": "mark_important",
"tags": [],
"reasons": {}
},
{
"tool": "mark_not_important",
"tags": [],
"reasons": {}
},
{
"tool": "trash_message",
"tags": [],
"reasons": {}
},
{
"tool": "untrash_message",
"tags": [],
"reasons": {}
},
{
"tool": "trash_thread",
"tags": [],
"reasons": {}
},
{
"tool": "untrash_thread",
"tags": [],
"reasons": {}
}
],
"surfaceDigest": "0f80fba3980a9a96efdc9b0e79d00cd9f3662bd9792c60a598651fcf9ec6aa1c",
"stats": {
"tools": 72,
"prompts": 0,
"resources": 0,
"findingsBySeverity": {
"critical": 0,
"high": 0,
"medium": 1,
"low": 0,
"info": 1
}
}
}