fetch_weather_forecast

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

With no annotations provided, the description carries the burden of behavioral disclosure. It does transparently describe the return format and error behavior (returning an 'error' key on failure). However, it does not mention potential prerequisites, rate limits, or side effects, though the tool is clearly a read-only operation. The error handling is a positive, but other behavioral aspects are omitted.

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 concise and well-structured. It promptly states the action, then details the argument and return value in a clear Args/Returns format. No words are wasted; every sentence contributes useful 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 the simplicity of the tool (one parameter, no annotations, limited schema), the description is fairly complete. It covers purpose, parameter semantics, return structure, and error handling. The only gap is the lack of explicit usage guidance relative to the sibling tool, but that is a minor omission for such a straightforward fetch 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?

The schema only provides a 'city' string with a title of 'City', and schema description coverage is 0%. The description compensates by explaining that the parameter is the 'Name of the city to fetch forecast data for', adding meaning beyond the schema. It could have provided more detail on city format, but for a single required parameter, it is helpful.

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 action ('Fetch the weather forecast') and the resource ('for a given city'). It also distinguishes itself from the sibling tool 'fetch_current_weather' by specifying '3-hour intervals' as part of the forecast data, making it clear this is for multi-period forecasts rather than current conditions.

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 implies usage when a forecast is needed, but it does not explicitly state when to use this tool over 'fetch_current_weather' or mention any exclusions. The '3-hour intervals' hint differentiates it, but no clear guidance on selection criteria is provided.

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