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

Annotations already declare read-only, idempotent, non-destructive, closed-world behavior, so the safety profile needs no restating. The description adds that each place is returned with a count, but says nothing about ordering, casing/normalization of names, or the result shape beyond counts.

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?

Two short sentences, zero filler, with the what-it-returns clause and the when-to-use clause each carrying distinct information.

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, read-only enumeration with no output schema, the description covers purpose, scope, and a rough sense of the payload (counts per place). A brief note on result ordering or name normalization would close the remaining gap.

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 no parameters, so the baseline applies. The description correctly implies a full unfiltered inventory rather than a scoped query, which matches the empty schema.

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?

Names a specific verb and resource ("Lists every city and district") and scopes it precisely to places holding a listed restaurant branch, including that counts are returned. That scope is distinct from listing cuisines, fetching a restaurant, or searching restaurants.

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?

Gives a concrete use case: look up the correct spelling of a place before searching within it, which implicitly routes the agent to the search tool next. It stops short of naming that sibling or stating when not to use this tool, so it is clear context rather than a full routing rule.

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