Zillow56 MCP Server

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It mentions output format options but doesn't describe what the tool actually does beyond 'Get a list of properties'. It doesn't disclose whether this is a read-only operation, whether it requires authentication, rate limits, pagination behavior, error conditions, or what the returned data structure looks like. For a tool with 4 parameters and no annotations, this leaves significant behavioral questions unanswered.

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 reasonably concise at two sentences. The first sentence states the core purpose, and the second mentions the output format option. However, the second sentence is incomplete (ends with 'using the optional "' which appears truncated) and could be more polished. Overall, it's front-loaded with the main purpose and avoids unnecessary verbiage.

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's complexity (4 parameters, no output schema, no annotations), the description is inadequate. It doesn't explain what kind of properties are returned, how many, in what structure, or what the URL parameter should contain. With no output schema and no behavioral annotations, the description should provide more context about the tool's operation and results. The incomplete second sentence further reduces completeness.

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 description coverage is 100%, so the schema already documents all parameters thoroughly. The description adds minimal value by mentioning the optional output format parameter, but doesn't provide additional context about parameter interactions, dependencies, or real-world usage patterns beyond what's in the schema. The baseline score of 3 is appropriate when the schema does the heavy lifting for parameter documentation.

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's purpose: 'Get a list of properties by providing the zillow search results URL'. It specifies the verb ('Get'), resource ('list of properties'), and key input mechanism ('by providing the zillow search results URL'). However, it doesn't explicitly differentiate from sibling tools like 'search_address_search_for_a_property_by_address' or 'search_coordinates_search_for_properties_by_coordinates', which appear to be alternative search methods.

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 no guidance on when to use this tool versus alternatives. It mentions an optional output format parameter but doesn't explain when this URL-based search approach is preferred over address-based, coordinate-based, or other search methods available in the sibling tools. There's no mention of prerequisites, limitations, or typical use cases for URL-based property searches.

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