Zillow56 MCP Server

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

No annotations are provided, so the description carries full burden. It states this is a 'Get' operation, implying read-only behavior, but doesn't disclose any behavioral traits such as authentication requirements, rate limits, response format, or error handling. For a tool with no annotations, this leaves significant gaps in understanding how it behaves beyond the basic purpose.

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, efficient sentence with zero waste. It's front-loaded with the core purpose and uses clear, direct language. Every word earns its place, making it easy to parse quickly without unnecessary elaboration.

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 no annotations and no output schema, the description is incomplete for a tool with 2 parameters. It lacks information on behavioral aspects like safety, response format, or error handling. While the purpose is clear, the overall context for an AI agent to use this tool effectively is insufficient, especially without structured data to fill the gaps.

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%, with both parameters ('zpid' and 'url') well-documented in the schema. The description adds no additional parameter semantics beyond implying 'zpid' is the primary lookup method. Since the schema does the heavy lifting, the baseline score of 3 is appropriate, as the description doesn't compensate but also doesn't detract.

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 verb ('Get') and resource ('a property's details'), specifying the lookup method ('by its zpid'). It distinguishes from siblings like search tools that find properties rather than retrieve details for a known property. However, it doesn't explicitly differentiate from similar tools like 'property_deprecated' or 'photos_photos_of_a_property' that might also provide property details.

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 doesn't mention whether to use this for known zpids versus other search methods, nor does it reference sibling tools like 'search_address_search_for_a_property_by_address' for unknown properties. The only implied usage is when you have a zpid, but no explicit context or exclusions are provided.

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