Get Rent Estimate

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

With no annotations, the description carries the full burden. It explains the AVM mechanism, mentions automatic lookup via lookup_subject_attributes, and discloses return contents ('point rent estimate plus a low–high range ... and the top comparable rentals'). It does not disclose failure modes or rate limits, but it clearly describes observable behavior for a read-only estimation tool.

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 that front-loads the main purpose, then covers input, recommendations, output, and usage context. No filler words, but it is somewhat long and could be tightened. Still, every sentence earns its place.

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 9 parameters and no output schema, the description sufficiently covers the main intent, input alternatives, optional parameter improvements, output structure, and complementary sibling usage. It doesn't mention every parameter (e.g., comp_count) but the schema fully defines those, and the description adds the missing high-level context about AVM behavior and return values.

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 baseline is 3. The description adds valuable relationships: 'For the sharpest estimate, also pass the property's propertyType, bedrooms, bathrooms, and squareFootage — or set lookup_subject_attributes=true' and 'Give an address, or a lat/long.' This explains how parameters interact and which combinations are recommended, exceeding schema-only 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 opens with a specific verb+resource: 'Estimate the fair-market LONG-TERM monthly rent for a property using RentCast's AVM.' This clearly distinguishes it from sibling get_value_estimate, which would be for property value rather than rent, and the explicit 'rent' and 'LONG-TERM monthly rent' phrases make the tool's purpose unambiguous.

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?

Provides explicit usage context: 'pair it with get_market_stats to compare an estimate against the zip-code average, or call it per-listing to rank rental opportunities.' It also offers input-method guidance ('Give an address, or a lat/long') and suggests parameter improvements for a sharper estimate. Missing a direct 'when not to use' or comparison with get_value_estimate, but the guidance is clear enough.

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