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

No annotations are provided, so the description must carry the behavioral burden. 'List' conveys a non-mutating enumeration and it discloses the return shape (city names plus slugs), which is useful, but it says nothing about ordering, scope limits, or whether results are paginated.

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 tightly written sentence with no filler, and the core purpose is front-loaded before the return-value note.

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 no-parameter enumeration tool with no output schema, the description covers what is returned (cities and their slugs) and why those slugs matter, which is enough for correct invocation. Minor gaps around result ordering/limits remain but are not blocking.

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 has zero parameters, so there is nothing to document; the baseline of 4 applies. The description correctly implies the tool takes no filters.

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 ('List') and resource ('US cities with building permit data'), and the trailing clause clarifies the payload (slugs). It is clearly distinguishable from siblings get_permit/permits_at_address/recent_permits, which all operate on individual permits, though it does not name them explicitly.

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 phrase 'each city's slug for the other tools' implies this is a discovery/prerequisite step feeding the sibling tools, but it never states when to call it or when it is unnecessary. Usage is implied rather than directed.

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