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

With no annotations, the description carries the full burden of behavioral disclosure. It discloses the 50¢ per-call cost, the availability restriction, and the exact fields returned. It does not state failure behavior for unlisted properties, rate limits, or data freshness, but it is much more transparent than a minimal query description.

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?

Two compact sentences with the key scope restriction and pricing clearly front-loaded. Every sentence earns its place and there is no filler.

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 one-parameter priced lookup, the description supplies purpose, availability condition, price, and output summary, while an output schema exists for return details. The main gap is explicit parameter documentation, but the overall call context is sufficient for correct invocation.

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?

The schema has 0% description coverage and the description never explains that gnaf_id is the property's G-NAF identifier or how to obtain it. It only ties the property concept to the call, so the parameter's meaning is mostly left to the parameter name and domain convention.

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 names the specific resource—the current listing agency's quoting accuracy—and lists concrete output components: cohort, median guide-vs-sold deviation, underquote rate, and 5 recent tracked sales. It does not explicitly name a sibling alternative, but the content clearly distinguishes it from the other properties_valuation_* tools.

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 sentence 'Only while the property is listed for sale with a tracked agency' gives a clear precondition and an implicit not-otherwise exclusion. It does not mention alternative valuation tools or explain when a different properties_valuation_* call should be used instead.

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