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

With no annotations, the description carries the full burden. It does disclose the return behavior by listing output fields and uses 'Searches'/'Returns' implying read-only, but it does not mention auth requirements, rate limits, or explicitly state that no data is modified.

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 compact and well-structured: a terse title line, a summary of functionality, and a list of use cases. It avoids unnecessary detail, though the opening 'Get Zillow Real Estate Listings' is slightly redundant with the tool name.

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 tool with 33 parameters and no output schema, the description provides sufficient context: what it searches, what it returns, and when to use it. It does not explain pagination defaults or required-field relationships, but the schema already marks 'keyword' and 'type' as required.

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% with descriptions for all 33 parameters. The description adds only a high-level grouping of filter types ('price, beds, baths, home type, year built...') rather than clarifying individual parameters, so it stays at the baseline.

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?

Description clearly states the tool 'Searches Zillow for-sale, for-rent, and sold listings by keyword' and specifies the output fields. It distinguishes from the sibling property-details tool by emphasizing listing search and 'collecting URLs for the Zillow Property endpoint.'

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?

Provides explicit use cases: 'real-estate market dashboards, rental pricing analysis, agent lead lists, inventory tracking, and collecting URLs for the Zillow Property endpoint.' This gives clear context for when to use the tool, though it doesn't explicitly say 'use this instead of getPropertyDetails.'

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