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Real-time US weather data via the National Weather Service API — forecasts, alerts, and observations.
Do not connect
A critical issue was found. Do not connect this server as-is.
Scanned 1 month ago Due for re-check
A server can change after it's graded. Re-run the automated scan to refresh this report.
This grade is deterministic and reproducible: the same server surface always yields the same grade under a given algorithm version. It is a real automated assessment computed by the MCPGrade engine from what the probe actually observed — not a fabricated or opinion score. It is not a manual human pentest, so it can miss context-specific risks.
Every signal below was measured directly by the automated probe. The grade is derived only from evidence like this — nothing is assumed.
The nws-weather-mcp-server MCP server exposes 7 tools, focused primarily on general-purpose capabilities. Its published description reads: "Real-time US weather data via the National Weather Service API — forecasts, alerts, and observations". It communicates over Streamable HTTP using the 2025-06-18 protocol revision, and does not require authorization to connect. MCPGrade currently rates nws-weather-mcp-server F — a critical issue was found and the server should not be connected as-is. Its most notable findings include "Data-exfiltration parameters" and "Cross-tool shadowing". This report is a deterministic, reproducible automated assessment: the same observed surface always yields the same grade under a given algorithm version, and it is refreshed as new scans arrive and free to read — but it is not a substitute for a manual human security review. Always re-check nws-weather-mcp-server's advertised tools, transport security, and authorization posture before connecting an autonomous agent or sharing sensitive context with it.
Add nws-weather-mcp-server to an MCP client using the endpoint below. Review the grade and findings above before granting an autonomous agent access.
MCP endpoint
https://nws.caseyjhand.com/mcpStreamable HTTP transport. This is the MCP endpoint, not a website — paste it into your MCP client server list rather than a browser.
Captured passively during the read-only scan. Click any value to find servers that match it.
The tools this server advertises via tools/list — names, purposes, and the parameters each accepts, exactly as enumerated read-only.
Get the weather forecast for a US location. Returns either named 12-hour periods (default) or hourly breakdowns.
Search active weather alerts (watches, warnings, advisories) across the US. Filter by state, coordinates, zone, land/marine region, event type, severity, urgency, or certainty. area, point, zone, regi
Sorted worst-first. Each finding shows its severity, what it means, its OWASP MCP Top-10 mapping, and a recommended fix — the check id links to the exact methodology row that produced it.
tool: nws_get_forecast
A tool exposes a free-text/webhook/feedback parameter with no honest purpose — a classic exfil channel.
ue continuation token from a previous response's nextCursor, to retriRecommendationRemove side-channel parameters; constrain tool inputs.
tool: nws_get_forecast
A tool description tries to alter the model’s use of another tool.
RecommendationDescriptions must describe only their own tool.
tool: nws_search_alerts
A tool exposes a free-text/webhook/feedback parameter with no honest purpose — a classic exfil channel.
ue continuation token from a previous response's nextCursor. Omit forRecommendationRemove side-channel parameters; constrain tool inputs.
tool: nws_find_stations
A tool description tries to alter the model’s use of another tool.
station IDs for nws_get_observations.RecommendationDescriptions must describe only their own tool.
tool: nws_list_alert_types
A tool description tries to alter the model’s use of another tool.
event filter in nws_search_alerts, or to browse alert categories. No parameters rRecommendationDescriptions must describe only their own tool.
tool: nws_get_office_discussion
A tool description tries to alter the model’s use of another tool.
ffice" field by nws_get_forecast.RecommendationDescriptions must describe only their own tool.
tool: nws_get_zone_forecast
A tool description tries to alter the model’s use of another tool.
forecast chain: nws_search_alerts returns each affected zone in "affectedZones" aRecommendationDescriptions must describe only their own tool.
tool: (server instructions)
A tool description tries to alter the model’s use of another tool.
Typical chain: nws_get_forecast → office code for nws_get_office_discussion (AFRecommendationDescriptions must describe only their own tool.
The server accepts tool enumeration (and likely invocation) with no authentication.
RecommendationRequire OAuth 2.1 authorization for any server exposing non-public tools.
Vantaj uptime monitoring via MCP — manage monitors, heartbeats, incidents, and status pages.
Unified gateway to Algeria's TKAWEN ecosystem: commerce, certification, and AI tools.
Provides access to the Cohereon Doctrine AI safety framework with governance components, tiered access, and agent onboarding.
Agentic rails for complex workflows with receipts, fees, and MCP tool access.
Structural TC39 spec lookup for ECMA-262 and ECMA-402 in AI agents, SHA-pinned and offline-first.
Structural TC39 spec lookup for ECMA-262 and ECMA-402 in AI agents, SHA-pinned and offline-first.
Get current weather observations (actual measured conditions). Accepts coordinates (resolves nearest station automatically) or a station ID directly (e.g., "KSEA").
Find weather observation stations near a location. Returns stations sorted by proximity with distance and bearing. Use to discover station IDs for nws_get_observations.
List all valid NWS alert event type names. Use to discover valid values for the event filter in nws_search_alerts, or to browse alert categories. No parameters required.
Get the latest narrative forecast product from a Weather Forecast Office (WFO). The default product is AFD (Area Forecast Discussion), which explains the meteorological reasoning behind the forecast —
Get the text forecast for a public NWS forecast zone. Returns named forecast periods (e.g., "Today", "Tonight", "Monday") with detailed narrative text — the human-readable, zone-level forecast written