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

Annotations already declare readOnly/idempotent/non-destructive, but the description adds substantial behavioral context: results are landlord-published and newest-first, the permit_verified flag's meaning, that get_rental exposes verification details, rent semantics, tenant_pays_service_fee, and how to handle empty results. This goes well beyond the annotations.

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 description is a single dense paragraph, but every sentence contributes: scope, usage, ordering, permit verification, filter categories, rent semantics, troubleshooting, and an example. It is somewhat long but not padded; the example is practical. It could be improved with structural separation, but it earns its length.

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 13 parameters, no output schema, and no required fields, the description covers purpose, usage, key result semantics (permit_verified, rent, service fee), filter categories, troubleshooting, and an example. It does not detail pagination/cursor behavior or list all result fields, but it provides enough for an agent to call correctly and interpret common output.

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 baseline is 3. The description adds extra semantics by explaining the filter categories, clarifying that rent is the listed monthly rent and that tenant_pays_service_fee indicates an added fee, and providing a concrete example of parameter combination. This adds value beyond the schema descriptions.

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 explicitly states the tool searches the A-du Rent inventory of ADU rentals, listing specific unit types and geographies. It further clarifies the intended use case ('find a small standalone rental in Southern California') and differentiates from get_rental by noting that tool returns verification details. This is a specific verb+resource with clear scope.

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 usage guidance ('Use this for any request to find a small standalone rental in Southern California') and troubleshooting advice when no matches are found. It references get_rental as a follow-up for permit verification, but does not explicitly contrast with other sibling search tools like 'search' or 'search_plans', so no exclusion guidance is provided.

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