MCP Quickstart Weather 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. While it indicates this is a read operation ('Get'), it doesn't disclose important behavioral traits like rate limits, authentication requirements, data freshness, error conditions, or what format the forecast returns. For a tool with zero annotation coverage, this leaves significant gaps in understanding how the tool behaves.

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 in the first sentence. The parameter documentation is structured clearly with an 'Args:' section. While efficient, the second sentence could be more polished (e.g., using 'Parameters:' instead of 'Args:').

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 (2 required parameters), no annotations, and no output schema, the description is incomplete. It doesn't explain what the forecast returns (temperature, precipitation, timeframe), error handling, or any limitations. For a weather API tool with zero structured metadata, the description should provide more complete operational context.

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?

The description explicitly lists both parameters (latitude and longitude) with brief explanations, adding meaningful context beyond the 0% schema description coverage. However, it doesn't provide format details (e.g., decimal degrees), valid ranges, or coordinate system information. The description compensates somewhat for the schema gap but doesn't fully document parameter semantics.

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 a specific verb ('Get') and resource ('weather forecast for a location'). It distinguishes itself from the sibling tool 'get_alerts' by focusing on forecasts rather than alerts. However, it doesn't explicitly differentiate between the two tools in the description text itself.

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 like 'get_alerts'. It simply states what the tool does without any context about appropriate use cases, prerequisites, or exclusions. There's no mention of when this tool is preferred over other weather-related tools.

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