Skip to main content
Glama

Open Meteo

by io.github.pipeworx-io
OverviewDiscussionsAdmin

Marine

marine
Read-onlyIdempotent

"Wave / swell / surf forecast for [beach]" / "sea conditions in [bay]" / "wave height at [coordinates]" / "is it safe to sail" — global marine weather forecast (wave height, wave period, wave direction, wind waves, swell waves) at any ocean lat/lng. Free, keyless. Use for surf reports, sailing prep, fishing conditions, coastal planning.

Input Schema

TableJSON Schema
NameRequiredDescriptionDefault
hourlyNoDefault wave_height,wave_period,wind_wave_height
latitudeYes
longitudeYes
forecast_daysNo

Output Schema

TableJSON Schema
NameRequiredDescriptionDefault
hourlyNoHourly marine forecast data
latitudeNoQuery latitude
timezoneNoIANA timezone string
elevationNoElevation of the location in meters
longitudeNoQuery longitude
hourly_unitsNoUnits for hourly marine variables
generationtime_msNoAPI response generation time in milliseconds
utc_offset_secondsNoUTC offset in seconds

Schema Changelog

Changes observed during successful MCP inspections.

  1. Changed2 schema fields changed
    • addedInput schema / examples
      Added value: +[
+  {
+    "latitude": 37.7749,
+    "longitude": -122.4194
+  },
+  {
+    "forecast_days": 5,
+    "latitude": -33.8688,
+    "longitude": 151.2093
+  }
+]
    • changedOutput schema / (root)
      Previous value: -nullNew value: +{
+  "properties": {
+    "elevation": {
+      "description": "Elevation of the location in meters",
+      "type": "number"
+    },
+    "generationtime_ms": {
+      "description": "API response generation time in milliseconds",
+      "type": "number"
+    },
+    "hourly": {
+      "additionalProperties": {
+        "items": {
+          "type": [
+            "number",
+            "null"
+          ]
+        },
+        "type": "array"
+      },
+      "description": "Hourly marine forecast data",
+      "properties": {
+        "time": {
+          "description": "ISO 8601 timestamps",
+          "items": {
+            "type": "string"
+          },
+          "type": "array"
+        }
+      },
+      "type": "object"
+    },
+    "hourly_units": {
+      "additionalProperties": {
+        "type": "string"
+      },
+      "description": "Units for hourly marine variables",
+      "type": "object"
+    },
+    "latitude": {
+      "description": "Query latitude",
+      "type": "number"
+    },
+    "longitude": {
+      "description": "Query longitude",
+      "type": "number"
+    },
+    "timezone": {
+      "description": "IANA timezone string",
+      "type": "string"
+    },
+    "utc_offset_seconds": {
+      "description": "UTC offset in seconds",
+      "type": "integer"
+    }
+  },
+  "type": "object"
+}
  2. First observed

TDQS

A3.7/5.0
Behavior3/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint, idempotentHint, destructiveHint false, and openWorldHint, which inform the agent about safety and idempotency. The description adds that it is 'free, keyless' and global, but does not disclose rate limits or data freshness. It does not contradict annotations.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness4/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is a single paragraph but is well-structured: it starts with example queries, then the core functionality, then use cases. It is concise and front-loaded with key information, though it could be more structured with bullet points.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness3/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the presence of an output schema, the description does not need to cover return values. It covers the tool's purpose, use cases, and parameters moderately. However, it lacks details on data source, update frequency, and does not fully describe all parameters. It is adequate but not comprehensive.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters2/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is only 25%, with only the 'hourly' parameter having a description. The description mentions the output variables (wave height, period, etc.) but does not explain the parameters beyond what the schema provides. For 4 parameters (2 required), the description should add more context but fails to do so.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the tool provides marine weather forecasts (wave height, period, direction, etc.) for any ocean location. It gives explicit example queries and use cases, and it clearly distinguishes itself from any sibling tools which are unrelated.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines4/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description explicitly lists appropriate use cases: surf reports, sailing prep, fishing conditions, coastal planning. It does not explicitly state when not to use or provide alternatives, but the tool's unique domain makes it clear. The sibling list contains no similar marine tool, so guidance is sufficient.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

All Open Meteo toolsInspect
Try in Browser
One endpoint for every MCP toolRayrun runs every MCP server behind one URL and holds the credentials. Each call is decided per client, tool, and argument, then recorded.ray.runAd

Glama MCP Gateway

Add one secure layer between your agents and this server.

Resources