Weatherapi Com MCP 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 mentions the 14-day forecast limit and JSON format, but lacks critical information about rate limits, authentication requirements, error conditions, or whether this is a read-only operation. The description doesn't adequately compensate for the absence of annotations.

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 concise with two sentences that efficiently convey the core functionality. It's front-loaded with the main purpose and includes key constraints (14-day limit, JSON format). While effective, it could be slightly more structured with clearer separation of different forecast components.

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 4-parameter tool with no annotations and no output schema, the description is insufficient. It doesn't explain what the return structure looks like (beyond 'json'), doesn't mention error handling, and provides no context about the sibling tools. The absence of output schema means the description should compensate by explaining return values, which it doesn't do.

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 parameters thoroughly. The description doesn't add any meaningful parameter semantics beyond what's in the schema - it mentions 'for a given city' which aligns with the 'q' parameter but provides no additional context about parameter interactions or usage patterns.

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: to return weather forecasts up to 14 days with astronomy data, daily forecasts, and hourly information for a given city. It specifies the verb ('returns') and resource ('weather forecast'), but doesn't explicitly differentiate from siblings like 'future_weather_api' or 'realtime_weather_api'.

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?

No guidance is provided on when to use this tool versus alternatives. With multiple weather-related sibling tools (future_weather_api, realtime_weather_api, etc.), the description offers no context about appropriate use cases, prerequisites, or distinctions from similar tools.

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