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

Annotations already declare readOnlyHint=true, so the description adds value by clarifying the nature of the nbhd* fields (POSITION not forecast) and referencing _units for more details. It also mentions the data source (FHFA back to 1975), which is extra context beyond the read-only annotation. 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 reasonably concise and front-loaded with the main purpose. The first sentence states the core function, the second adds clarifying nuance about nbhd* fields, and the third lists the property_type enum. It could be slightly tighter, but each sentence earns its place without 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?

Given no output schema, the description outlines major outputs (forecast, rent, neighborhood signals) and clarifies the nbhd* fields' meaning. However, it omits how bedrooms influences results, what 'estimated market rent' means precisely, and does not mention any error cases or rate limits. For a read-only tool, it is adequate but 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%, so the description must compensate. It provides the property_type enum (sfr | condo | townhome | multi) and clarifies address can be a bare 5-digit ZIP. However, it gives no guidance on the bedrooms parameter's effect or expected format, leaving a gap for the agent. The description partially addresses parameter semantics but not sufficiently given zero schema coverage.

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 looks up a US address or ZIP and returns specific outputs: home-price appreciation forecast, estimated market rent, and neighborhood signals. It uses a specific verb ('Look up') and resource, and distinguishes itself from siblings by listing its unique outputs (FHFA data, rent, neighborhood signals) that are not covered by the sibling tools like affordability or buy_vs_rent.

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 usage context by differentiating between bare ZIP and full street address, explaining that full addresses return additional nbhd* fields. It also clarifies that these fields are positional, not forecasts, which helps the agent avoid misinterpretation. However, it does not explicitly state when to prefer this tool over alternatives like compare_areas, though the unique output set implies it.

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