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

Annotations already establish readOnlyHint=true and openWorldHint=false, so the safety profile is covered, yet the description still adds real value: pricing is fully loaded (cleaning and 5% GST included, no service fee), a link is returned per home, and the guest may book on-page or through the agent. That last clause usefully telegraphs the follow-up action. It doesn't describe result limits or pagination, keeping it off a 5.

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 dense sentences with no filler; scope and price inclusiveness are front-loaded before the booking handoff. It loses a point only because it reads as a noun-phrase fragment rather than a directed instruction, which makes the opening marginally slower to parse.

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 burden and does so reasonably: it says what is returned (available homes with links and all-in totals) and what happens next. A 3-parameter read-only tool needs little more, though capacity rules beyond the schema's guests max and any minimum-night constraints are unaddressed.

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 67%: check_in and check_out are documented as YYYY-MM-DD and guests is constrained 1-20 but left without a description. The phrase 'free for the dates' reinforces that the two date parameters are an availability window, which is slight added meaning over the schema. Baseline 3 is appropriate given the schema does most of the work.

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?

The description names the resource precisely (private homes), the geography (Vancouver, Burnaby, West Vancouver BC) and the filter (free for the dates), so an agent knows exactly what this returns without opening the schema. It stops short of a leading verb, and the distinction from book_stay is only implied via the closing booking sentence rather than stated as a contrast.

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 implied rather than stated: dates plus guests are required, and the closing line ('the guest can book on the page or ask you to book') gestures at the handoff to book_stay. There is no explicit 'call this first, then call book_stay' sequencing and no statement of when not to use it.

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