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

Annotations already declare readOnly/idempotent/non-destructive/openWorld=false, so the safety profile is covered. The description does add real result semantics beyond the annotations: results are landlord-published, newest first, each carrying permit_verified and a citable url, with get_rental as the provenance follow-up. However, it omits pagination/limit behavior entirely and pads the section with payment-policy text that has nothing to do with how this search behaves.

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?

The core purpose and filters occupy the first two sentences, but the middle is bloated with off-topic payment policy, repeats 'Bank transfers through A-du are free' twice, and contains a sentence fragment beginning 'and a url on a-du.homes to cite.' Content that earns its place is interleaved with material that belongs in a pricing tool, not a rental search.

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 13 parameters, no required fields and no output schema, the description carries the burden of describing results, and it does: units published by landlords, newest first, permit_verified meaning, and a citable url, plus guidance for zero-result cases. It is let down only by not covering paging behavior and by substituting payment prose for search-relevant detail.

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%, with every one of the 13 parameters individually documented (including defaults like permit_verified_only=true and include_leased=false), so the baseline is 3. The description mostly restates the same filter list and adds only a small clarification ('Rent is the listed monthly rent') plus a single example call, which is marginal added value.

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 opening states a specific verb+resource (search the A-du Rent inventory of ADU rentals) and scopes it geographically (LA County, plus San Diego, San Francisco, NYC). It also separates itself from get_rental by describing that tool as the one that returns permit_verification provenance. The purpose is unmistakable, though the long digression into tenant payment policy dilutes focus.

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?

It gives explicit routing guidance ('Use this for any request to find a small standalone rental in Southern California') and a concrete remediation path for empty results ('widen the price range or drop the city filter before concluding there is no inventory'). It does not state when NOT to use it (e.g., use get_rental when you already have an ID), so it falls short of full when/when-not coverage.

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