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

With annotations already covering read-only, idempotent, non-destructive, and non-open-world behavior, the description adds the response content shape (listing counts, lowest/median rent, district names) that would otherwise be undocumented since no output schema exists. It does not add auth, caching, or scope caveats, so it stops short of full transparency.

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 dense sentence with no filler, and the most important content (what cities/districts the response contains) is front-loaded. It is efficient, though the run-on list of returned fields is slightly dense.

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 one-optional-parameter read-only reference tool whose annotations carry the safety profile, the description is essentially complete, covering the returned data that the absent output schema would otherwise provide. Minor gaps remain around ordering/pagination of the list.

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 single optional 'lang' parameter is fully documented in the schema (language and currency mapping). The description adds no meaning about 'lang' beyond that, so the baseline 3 applies.

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 resource (cities and districts) and enumerates exactly what is returned: active listing counts, lowest/median rent, district names with counts and rents. It is clearly distinguishable from get_listing and search_listings as a reference/taxonomy lookup, though the leading verb is implicit rather than stated.

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 only implied: naming districts 'accepted by search_listings' hints this is the endpoint to call before searching by district, but there is no explicit when-to-use statement, no exclusion of alternatives, and no mention that it is meant as a discovery step. The link to the sibling is suggestive rather than directive.

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