List Available City Data

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

No annotations are provided, so the description carries the full burden. It discloses what is returned (supported cities and their data categories), which is useful behavioral context, but does not explicitly state that the operation is read-only, has no side effects, or requires no authentication. For a zero-parameter listing tool these are minor gaps, but the description could be more transparent about safety and return 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?

Two short sentences with zero waste; the core action and its purpose are front-loaded. Every sentence earns its place, making it easy for an agent to parse quickly.

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 low complexity (0 parameters, no output schema), the description adequately explains what it returns and why to call it. It could specify the return format more precisely, but for a simple discovery endpoint it is sufficiently complete.

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?

There are zero parameters, so per the rubric the baseline is 4. The description adds no parameter information because none exist, and the schema already fully covers the empty input object.

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 states a specific verb ('List') and resource ('all supported cities and the data categories available for each'), clearly distinguishing this discovery tool from the many query_* siblings that retrieve actual data. An agent can tell immediately that this tool returns a catalog, not query results.

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?

It explicitly says 'Use this to discover what data you can query,' which gives clear context for when to call it before using query tools. However, it does not name specific alternatives or state when not to use it (e.g., if you already know the city/category).

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