zillow_listing: GET /

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

There are no annotations, so the description carries the behavioral burden, and it does a good job by specifying both the search behavior and the returned data: 'address, Zillow URL/zpid, price, Zestimate, beds/baths, sqft, home type, status, days on Zillow, coordinates, thumbnail, listing agent.' It also states 'pagination' as part of the behavior. It does not cover rate limits or errors, but for a listing search this is largely background.

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 appropriately sized and front-loaded: it starts with the operation, then covers filters and return fields, then adds use cases. The prose is reasonably brisk for a 33-parameter tool, and most sentences earn their place; only a few phrases just echo the schema or the tool name.

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 a tool with 33 parameters, no output schema, and no annotations, this description is unusually complete. It covers what the tool searches, what filters are possible, what fields come back, how pagination works, and why someone would use it, plus it connects downstream to the sibling Property endpoint. An agent has what it needs to select and invoke the tool correctly.

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?

Input schema coverage is 100%, so every parameter already has a structured description. The tool description adds an organized summary of the main filter categories—'price, beds, baths, home type, day built, lot/square footage, HOA, listing status, amenities, views, pet policy, days on Zillow'—but it does not substantially promote per-parameter meaning beyond the schema.

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 and resource ('Get Zillow Real Estate Listings') and explicitly states it 'Searches Zillow for-sale, for-rent, and sold listings by keyword with rich filters'. It clearly distinguishes itself as a listing-search tool rather than a property-detail tool, and the closing note about 'collecting URLs for the Zillow Property endpoint' reinforces that distinction.

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?

The description provides concrete intended use cases: 'real-estate market dashboards, rental pricing analysis, agent lead lists, inventory tracking, and collecting URLs for the Zillow Property endpoint.' It gives a clear sense of when to choose this tool, though it does not explicitly name the sibling tool or state 'use getPropertyDetails when you already have a zpid.'

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