Open-Meteo MCP Server

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

No annotations are provided, so the description carries full burden for behavioral disclosure. It states the tool retrieves forecast data but doesn't describe critical behaviors: whether it's a read-only operation, requires authentication, has rate limits, returns real-time or historical data, or how forecasts are generated. The mention of 'forecast' implies future data, but behavioral context is minimal.

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

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

The description is a single, efficient sentence that front-loads the core purpose without unnecessary words. Every element ('Get marine weather forecast including...') directly contributes to understanding the tool's function. There's zero waste or redundancy.

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

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

Given the tool's moderate complexity (7 parameters, no output schema, no annotations), the description is minimally adequate. It states what the tool does but lacks context about behavioral traits, usage compared to siblings, or output format. Without annotations or output schema, the description should ideally provide more operational context, but it meets a basic threshold for a data retrieval tool.

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

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

Schema description coverage is 100%, so the schema fully documents all 7 parameters. The description adds no parameter-specific semantics beyond implying location-based queries through 'marine weather forecast'. It lists example data points (wave height, period, etc.) that correspond to 'hourly' enum values, but this doesn't provide additional meaning beyond what the schema already specifies with its enum arrays and descriptions.

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

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

The description clearly states the tool's purpose: 'Get marine weather forecast including wave height, wave period, wave direction and sea surface temperature.' It specifies the verb ('Get') and resource ('marine weather forecast') with concrete examples of data points. However, it doesn't explicitly differentiate from sibling weather tools like 'weather_forecast' or 'dwd_icon_forecast' beyond mentioning 'marine' focus.

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

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

The description provides no guidance on when to use this tool versus alternatives. With multiple sibling tools for weather, climate, and forecasts (e.g., 'weather_forecast', 'ensemble_forecast', 'climate_projection'), there's no indication of when this marine-specific tool is appropriate or what distinguishes it from general weather tools. Usage is implied by the 'marine' keyword but not explicitly stated.

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