List cities

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

Annotations already declare readOnly, idempotent, openWorld and non-destructive, so the safety profile is covered. The description adds the one thing annotations cannot convey: that results are identifier mappings (slug and id) rather than free-form text, which matters with no output schema. It does not mention whether the list is complete, cached, or paginated, leaving a small gap.

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?

A single sentence that front-loads the action and then spends its remaining words on the highest-value detail, the cross-tool identifier mapping. No filler, no restatement of the title.

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 zero-parameter list tool with no output schema, the description covers the essentials: what is listed and what identifiers come back. It leaves the remaining return fields (e.g., a display name) unstated, which is a minor omission rather than a blocker.

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 takes zero parameters, so the schema baseline is 4 and there is nothing further for the description to disambiguate. The mention of `city` and id refers to how returned values feed sibling tools, not to inputs, so it does not create schema confusion.

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?

States a specific verb and resource ('List the cities Karnameh serves') and immediately disambiguates the returned identifiers by naming the exact field names used by two siblings ('the slug kn_cars takes as `city` and the id kn_inspection_centers takes'). An agent can distinguish this lookup tool from kn_city_stats or kn_inspection_centers without opening any schema.

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?

Usage is strongly implied by tying the outputs to kn_cars' `city` parameter and kn_inspection_centers' expected id, which tells the agent this is a prerequisite lookup. There is no explicit 'use this before X' statement or any when-not guidance, so it stops just short of full routing instructions.

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