MCP Weather Server

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

With no annotations provided, the description carries full burden for behavioral disclosure. It states the tool returns data for 'the next 24 hours' and implies a default location, but doesn't cover error handling, rate limits, authentication needs, or data freshness. For a weather API tool with zero annotation coverage, this leaves significant gaps in understanding operational behavior.

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 two concise sentences that efficiently convey the core functionality and scope. Every word earns its place with no redundancy or fluff, making it easy to parse and front-loaded with essential information.

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 no annotations and no output schema, the description is incomplete for a weather forecasting tool. It lacks details on return format (e.g., what data fields are included), error cases (e.g., invalid location), and how it integrates with sibling tools, leaving the agent with insufficient context for reliable use.

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 both parameters (location and options with nested fields). The description adds no parameter-specific information beyond what's in the schema, such as format examples for location or default values beyond hours=24. This meets the baseline for high schema coverage.

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 hourly weather forecast for a location' with the specific scope 'hour by hour for the next 24 hours.' It distinguishes from siblings like 'getWeather' (likely current weather) and 'getWeatherForecast' (likely daily forecast) by specifying hourly granularity, though it doesn't explicitly name these alternatives.

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 its siblings (getWeather, getWeatherForecast, lookupCity). It mentions the default 24-hour scope but doesn't clarify if this is the only option or how it differs from other forecast tools, leaving the agent to infer usage context.

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