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

Annotations cover read-only and open-world, and the description adds real context beyond them: it reads exactly one public page, performs no Airbnb-side search, and returns an explicit 'no offers' outcome when the home isn't listed elsewhere. The only gap is that it doesn't discuss latency, rate limits, or failure modes when the page can't be read.

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?

Three sentences, front-loaded with the core action and return shape, then scoping constraint, then the no-match outcome. Nothing is repeated from the schema and no sentence is filler.

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?

With no output schema, the description carries the return contract itself and does so fully: per-match all-in total including fees and taxes, savings vs. the Airbnb total, confidence, link, and price-check timestamp. The empty-result case is also covered, so an agent knows how to interpret a success response.

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 all eight parameters including guest breakdowns and airbnb_total are already documented in structured form. The description only restates the URL-plus-dates framing and the savings concept, adding no format or constraint detail the schema doesn't already carry — baseline 3 is correct.

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 — given an Airbnb listing URL, find the same home bookable elsewhere (HomeShared or host site) and return matches with totals, savings, and confidence. The clause 'Reads only that one public Airbnb listing page; it doesn't search Airbnb' separates it cleanly from search_stays, so an agent can route without opening the 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?

The trigger is explicit (you have an Airbnb listing URL plus dates) and there is a clear when-not in 'it doesn't search Airbnb', which points an agent toward the search sibling for discovery. It stops short of naming search_stays/get_quote/book outright, so the alternative routing is implied rather than spelled out.

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