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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), and the description adds substantial behavior beyond them: nearest-first ordering, five per page, straight-line whole-mile distances measured between town centers, daily-rotation tie-breaking, and totalMatches/nextCursor pagination. The fallback behaviors for ambiguous city names and misspellings are disclosed rather than left to discovery.

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?

Four dense sentences, front-loaded with what the tool returns and its ordering, then the parameter caveat, then the result shape, then edge cases. Every clause carries operational information; nothing is repeated from the schema or 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?

There is no output schema, so the description must carry the return contract, and it does: it enumerates every result field, the totalMatches count, and nextCursor for continuation. For a five-parameter read tool with full annotation coverage, nothing an agent needs in order to call it or interpret the answer is missing.

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 coverage is 100%, so the schema already documents each parameter and the baseline would be 3. The description still adds meaning: it fixes the semantics of `city` as the destination, not the caller's location, and supplies a default page size of five that the schema itself does not state for `limit`. It does not clarify the interaction between `state` and `city` beyond noting that multi-state names return candidates.

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 ("Lists live Booking Bench sites that have rental units") plus scope (in or near a US destination city), ordering (nearest first) and page size (five per page). An agent can tell this apart from list_properties, which returns units rather than sites, without opening either 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?

Gives explicit context for the ambiguous case: "`city` is the destination the traveler names, never the traveler's own location," which is the main way this call could be misused. It also explains the multi-state and misspelling outcomes. It stops short of naming a sibling or stating when-not to use it, so it does not reach the top band.

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