List Supported Prayer-Time Cities

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

With no annotations, the description carries the burden of explaining behavior. It mentions that the tool lists 20 major cities, provides examples, and notes it takes no parameters. It conveys that this is a safe, read-only lookup, though it does not explicitly state the return format or ordering, which would have made it fully transparent.

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 sentences, brisk and informative. It front-loads the purpose, then adds usage guidance and a note about parameters. No wasted words—every segment earns its place.

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 simple parameterless listing tool, the description is complete: it explains the purpose, gives examples, and tells when to use it alongside its sibling tool get_prayer_times. A small gap is the lack of an explicit note about the output type (e.g., array of slug strings), but given the straightforward nature, this is not a critical omission.

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 tool has zero parameters, so per the rubric the baseline is 4. The description correctly notes 'Takes no parameters,' which is consistent but does not add extra semantic depth beyond the schema. This is acceptable given the absence of parameters.

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 function with a specific verb ('List') and a specific resource ('Turkish city slugs supported by get_prayer_times'). It distinguishes itself from sibling tools by being a supporting lookup specifically for get_prayer_times, and provides concrete examples (istanbul, ankara, izmir).

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 explicitly states when to use the tool: 'Call this before get_prayer_times when you are not sure a city is supported or how its slug is spelled.' This gives clear, actionable guidance with a condition, which is ideal for an AI agent deciding which tool to invoke.

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