list_cities

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

No annotations are provided, so the description carries the full burden for behavioral disclosure. It does indicate the operation is a read/list operation (not destructive), and that it is scoped by a state/region, which is useful. However, it does not mention that the result may be filtered by number availability, whether it returns a simple array or paginated results, or any prerequisites. The behavior is minimally transparent but not rich.

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 a single sentence with no fluff, and it front-loads the purpose ('List cities with available numbers') and the scope ('for a state / region'). It earns its place with no wasted words.

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 is a straightforward list operation with only one required parameter, the description is fairly complete. However, with no annotations, no output schema, and an ambiguous relationship to sibling tools like 'list_available_numbers', it could provide more context about what the response contains or when to choose this over more specific listing tools. Overall, it is adequate but not fully 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?

The schema covers all parameters (100% coverage) with a clear description for 'state' (State or region code with examples). The tool description itself does not add further parameter semantics, but since the schema is complete, a baseline 3 is appropriate. The description's phrase 'for a state / region' does reinforce the parameter's meaning, but no additional format details are given.

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 a specific verb ('list') and resource ('cities with available numbers') and adds context about the scope ('for a state / region'). It is likely distinct from the broadly similar 'list_available_numbers' and 'list_destinations', though it does not explicitly name those siblings, so it earns a 4 rather than a 5.

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 the primary use case (finding cities where numbers can be purchased) by mentioning 'available numbers', but it does not explicitly explain when to use this versus 'list_available_numbers', 'list_destinations', or other sibling tools. The usage guidance is implied from the context rather than directly stated, so a 3 is appropriate.

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