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

Annotations already mark the tool read-only and open-world; the description adds meaningful behavior: no listing inventory, no autonomous ZIP discovery, ranking coverage limited to passed ZIPs, and a guarantee of correct city names. No contradiction with annotations exists.

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 front-loaded with the core action and uses compact phrasing throughout. Every sentence contributes either the signal list, a use case, or a necessary limitation; there is no filler or redundancy.

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?

Despite no output schema, it conveys what comes back (ranking and correct city names) and covers input constraints and limitations well. The main gaps are the unexplained 'bedrooms' parameter and the absence of explicit alternatives, so it is not fully complete.

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 0%, and the description compensates for the required addresses parameter by adding constraints like 2-12 inputs and 'pass that metro's ZIP codes.' However, the optional 'bedrooms' parameter is never explained, leaving a notable semantic gap for a call 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?

Description clearly states the action ('Analyze and RANK 2-12 ZIPs or addresses side by side') and enumerates the concrete signals compared. It also distinguishes the tool from single-address/listings tools by noting TerraVue has no listing inventory and cannot discover ZIPs on its own.

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?

Explicitly provides a use-case ('which areas have the best appreciation / schools / upside') and instructs the caller to pass metro ZIP codes since the tool cannot discover them. It does not explicitly name sibling tools or state when to prefer alternatives like analyze_address or affordability, so it stops short of a 5.

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