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

Annotations already establish read-only, idempotent, non-destructive, closed-world behavior. The description adds meaningful context beyond that by scoping results to cities that actually have a page and by stating that upcoming date counts and slugs are returned. It does not mention ordering or pagination, but for a small read-only list tool this is largely sufficient.

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 efficient sentence with no filler. The scope is front-loaded and the returned fields are named immediately. Nothing is wasted or buried.

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 read-only list tool with one fully documented optional parameter and no output schema, the description gives enough context: which cities are included, what is returned, and how the slug is used. Ordering or pagination behavior is absent, but the core contract is complete enough to call the tool correctly.

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?

Schema description coverage is 100%, and the locale parameter is fully described with its enum and default in the schema. The description does not add any parameter-specific meaning beyond what the schema already provides. Baseline 3 is appropriate.

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 identifies the resource as every city with a Lineup Atlas page and names the returned fields (upcoming date count and slug). It also links the slug to get_city, helping distinguish this discovery tool from the detail tool. The verb 'list' is only implied by 'Every city', but the intent is still clear.

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 that this tool is used to discover cities and that the returned slug feeds into get_city. However, it does not explicitly say when to use this versus search or get_city, nor does it state any exclusions. Usage guidance is therefore present but incomplete.

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