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

Annotations already declare readOnly/openWorld-false, so the description correctly focuses on provenance: figures come from live dealer listings, each carries a listing and dealer count for sample-size judgment, and the asking-vs-sale-price caveat is a critical honesty signal. It stops short of stating listing recency or refresh cadence, which matters for a 'current listings' claim.

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?

Three sentences, front-loaded with what is measured and from where, then coverage scope, then the key caveat. Every sentence carries distinct information with no repetition of 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?

With no output schema, the description does the necessary work of naming the returned fields (median price, mileage, model year, listing count, dealer count) and the data domain. It omits units/format and how far back model years go, which an agent might want before presenting results.

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% and the single enum param is fully documented, so baseline is 3. The description earns above that by explaining data coverage per category — notably that mileage extends to motorcoaches beyond the price categories — though four of the eight enum values (type-a-school-bus, activity-bus, shuttle-bus, transit-bus) go unaddressed and the motorcoach wording is ambiguous about whether price data exists there.

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?

States a specific resource (median asking prices and mileage for used buses by model year) plus the data source (current dealer listings on CommercialBuses). This clearly separates it from listing-oriented siblings like search_buses and get_bus: this returns aggregate statistics, not individual vehicles.

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?

No explicit when-to-use or when-not-to-use statement, and no alternative tool is named. The coverage sentence (prices for school/cutaway/paratransit, mileage also for motorcoaches) implies when results are meaningful, but the agent must infer the routing vs. search_buses or get_buying_context on its own.

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