Get Zillow market report for a region

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and openWorldHint=true. The description reinforces this with 'Read-only; safe to call repeatedly' but adds no new behavioral context such as rate limits, authentication needs, or error behavior. No contradiction with annotations is present.

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 two tight sentences, front-loading the core purpose and metrics, then giving input instructions and safety reassurance. There is no filler or redundant expansion.

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 read-only tool with two documented optional params and no output schema, the description adequately prepares an agent by listing the expected report contents and the acceptable input forms. It would be slightly stronger if it explicitly stated the one-of requirement and possible behavior when neither parameter is supplied.

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 coverage is 100%, so both parameters are already documented. The description adds the key semantic insight that the parameters are alternatives — 'Provide either a region_path ... or a full Zillow home-values URL' — which is not encoded in the schema's optional-parameter structure.

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 fetches a market report for a Zillow region and enumerates the specific metrics included (median sale/list prices, days on market, inventory, new listings, ZHVI, and YoY change). This is a specific verb+resource and it distinguishes the tool from property-level, search, and comparison siblings.

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 implies when to use the tool via its purpose, but it does not explicitly state 'use this when you need regional market stats' or mention any alternatives. It does give a clear instruction to provide either a region_path or a full URL, which is useful, but no exclusionary guidance versus sibling tools.

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