Zillow56 MCP Server

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

No annotations are provided, so the description carries the full burden. It only states what the tool does ('Get agent's active listings'), without disclosing behavioral traits like pagination details (implied by 'page' parameter), rate limits, authentication needs, error handling, or what 'active listings' entails. This leaves significant gaps for a read operation.

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: 'Get agent's active listings by zuid'. It's front-loaded with the core purpose, has zero wasted words, and is appropriately sized for a simple tool.

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. It lacks details on return values (e.g., format of listings), pagination behavior (implied by 'page' parameter), error cases, or what qualifies as 'active'. For a tool with 2 parameters and no structured output, this leaves the agent with insufficient context.

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 ('zuid' and 'page'). The description adds no additional meaning beyond implying 'zuid' is required for fetching listings. With high schema coverage, the baseline is 3, as the description doesn't compensate with extra context.

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 agent's active listings by zuid'. It specifies the verb ('Get'), resource ('agent's active listings'), and key identifier ('by zuid'). However, it doesn't explicitly differentiate from sibling tools like 'agents_past_sales' or 'agents_rental_listings', which would require a 5.

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 sibling tools like 'agents_past_sales' or 'agents_rental_listings', nor does it specify prerequisites or contexts for usage. The agent must infer usage from the name alone.

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