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

The annotations already declare readOnlyHint, openWorldHint, and idempotentHint, so the description's main added value is detailing response contents and approximate size (~17 KB). It also clarifies that every zpid has a record, whether listed or off market, which is useful behavioral context. No contradiction with annotations.

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 dense but well organized, with the resource and scope stated up front and then cleanly labeled sections for compact vs expanded output. Every phrase contributes information, and there is no filler or repetition.

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?

With no output schema, the description carries the burden of explaining what the tool returns, and it does so thoroughly by enumerating both the compact fields and the expanded additions such as history, schools, scores, nearby homes, and photos. The description is complete enough for an agent to decide when to invoke this tool and which mode to use.

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 the baseline is 3. The description adds meaningful detail beyond the schema by explaining what the compact form includes, what expand true unlocks, and that pricing is the same either way. This genuinely helps an agent decide how to set the boolean parameter.

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 identifies the target as the property record for any zpid, including off-market listings, and distinguishes it from specialized siblings by offering a full or compact record. It lacks an explicit retrieval verb like "gets" or "fetches" and does not name sibling alternatives, which keeps it from 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?

It provides clear context: use the default compact form for the headline, or set expand true for the complete record. It explains the key decision point between the two modes, but it does not explicitly say when to prefer sibling tools such as zillow_property_facts or zillow_price_history, so exclusions and alternatives are missing.

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