List Active Listings

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

With no annotations, the description carries the full burden and does so impressively. It discloses that RentCast does not filter by price server-side and the agent must filter/rank by returned price. It also reveals ordering (most recently seen first), price units (USD, sale total vs monthly rent), and downstream API cost implications for the limit parameter.

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 information-dense yet compact. It front-loads the core purpose, then covers scoping, return format, key caveats, and a workflow example. Every sentence earns its place without fluff or repetition.

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 an 8-parameter tool with no output schema, the description is remarkably complete. It specifies the return structure (id, address, price, beds/baths, square footage, days on market, status), explains the price filter absence, and shows how the tool fits into a larger workflow with sibling tools. No critical gaps remain.

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?

Though schema coverage is 100%, the description adds meaningful context: it explains how listing_type selects the market, how city+state work together, and warns that keeping limit modest matters because each downstream rent estimate is a separate API call. This goes beyond the schema's raw parameter definitions.

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 states the tool lists currently active sale or rental listings with a clear verb+resource+scope ('List CURRENTLY ACTIVE sale or rental listings for an area'), and explicitly distinguishes it from search_properties, which searches historical property records. This makes the purpose unambiguous and differentiates it from a sibling.

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 says when to use this tool ('entry point for workflows') and provides a concrete example: 'find 3-bed listings in <city> under $X, then estimate rent for each' — feed each result's address to get_rent_estimate. It also explicitly contrasts with search_properties, offering an alternative and exclusion.

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