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

Annotations declare read-only, open-world, idempotent, and non-destructive. The description adds useful behavioral context: record shape mirrors search_sale_listings, each record is tagged listingKind:'rental-long-term', and upstream cache is 30 minutes. This goes beyond annotations and helps set expectations.

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 sentences, front-loaded with the action, and every phrase adds value (lease term, shape, tag, cache). No fluff.

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?

Given the tool has 19 parameters and no output schema, the description references search_sale_listings for record shape, which provides a compact way to communicate return structure. It covers pagination ('page'), listing type, location rules, and cache behavior. It could be more self-contained without relying on sibling knowledge, but is adequate.

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?

The input schema has 100% description coverage for all 19 parameters, so the schema already provides full parameter semantics. The description adds no additional parameter meaning, just references the overall shape and cache, so a baseline score of 3 is appropriate.

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 clearly states the tool returns rental listings with a specific lease term ('long-term (12-month lease)'), and distinguishes itself from the sibling search_sale_listings by noting the same record shape but with a listingKind tag and monthly price as rent.

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 context by referencing search_sale_listings and stating 'Same location-pinning rules and 30-minute upstream cache', implying this tool behaves like the sale-listings endpoint but for rentals. It does not explicitly exclude other tools but the rental/sale distinction is clear.

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