Open-Meteo MCP Server

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It explains what the tool returns ('geographic coordinates and detailed location information') and its essential purpose in converting names to coordinates. However, it doesn't mention rate limits, authentication requirements, error conditions, or whether this is a read-only operation versus a write operation. The description adds value but leaves significant behavioral aspects unspecified.

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 appropriately sized and front-loaded, with the core purpose stated in the first sentence. The second and third sentences provide valuable usage context. While efficient, the third sentence could be slightly more concise by combining concepts about when to use the tool.

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?

For a search tool with no annotations and no output schema, the description provides good context about what the tool does and when to use it. It clearly distinguishes this from sibling weather tools. However, without annotations or output schema, it could better explain the return format, error handling, or limitations of the geocoding service.

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 already documents all 5 parameters thoroughly. The description doesn't add any parameter-specific information beyond what's in the schema. It mentions the 'name' parameter implicitly ('location name or postal code') but provides no additional syntax, format, or usage details. Baseline 3 is appropriate when the schema does the heavy lifting.

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 with specific verbs ('search for locations', 'convert a location name into precise coordinates') and resources ('geographic coordinates', 'detailed location information'). It explicitly distinguishes this geocoding tool from sibling weather/forecast tools by focusing on coordinate conversion rather than meteorological data.

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 explicit guidance on when to use this tool: 'when you need to convert a location name into precise coordinates that are required by other tools' and 'when you have a location name but need coordinates for data fetching tools.' This clearly differentiates it from sibling tools that provide weather data rather than coordinate conversion.

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