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 it 'Returns' data, implying a read-only operation, but doesn't disclose behavioral traits like authentication needs, rate limits, error conditions, or response format. For a tool with no annotation coverage, this is a significant gap in transparency about how it behaves.

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 that front-loads the core purpose ('Returns a property's photos') and adds useful detail ('with different sizes and types'). There is no wasted text, making it appropriately sized and well-structured for quick understanding.

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, no output schema, and a simple input schema, the description is minimally complete for a read operation. It covers the purpose and output characteristics but lacks behavioral context (e.g., response format, errors) and usage guidelines. For a tool with low complexity, this is adequate but has clear 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%, so the schema already documents both parameters (zpid and url) with clear descriptions. The description adds no parameter-specific information beyond implying the tool operates on a property. Baseline 3 is appropriate as the schema handles parameter documentation adequately.

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 ('Returns') and resource ('a property's photos'), specifying what the tool does. It adds detail about output characteristics ('with different sizes and types'), which helps distinguish it from general property details tools. However, it doesn't explicitly differentiate from potential photo-related siblings (none are listed, but context suggests it's unique in this server).

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?

No guidance is provided on when to use this tool versus alternatives. The description doesn't mention prerequisites, context for photo retrieval, or comparisons to other property data tools (e.g., propertyv2_property_details_by_zpid might include photos). This leaves the agent without usage direction beyond the basic purpose.

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