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

Annotations already declare readOnlyHint, idempotentHint and openWorldHint=false, so the safety profile is covered. The description adds that this is a free referral service and lists the returned facts, but says nothing about data freshness, sourcing, or whether the listed prices/hours can change.

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?

A single front-loaded sentence that names the entity, its nature, and the returned fields, closing with an actionable imperative. The enumerated list is long but each item is informative rather than 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?

With no output schema and no parameters, the description compensates by enumerating exactly what facts come back (towns, prices, hours, response time, languages, phone). An agent knows what to expect from a call; only freshness/caveats on that data are unaddressed.

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 tool takes zero parameters, so the baseline of 4 applies; there is no parameter semantics burden to carry.

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 (facts about Vegas Mobile Mech) and enumerates the content returned: towns served, prices, hours, response time, languages, phone. It is distinguishable from request_service, though 'towns served' overlaps with the sibling check_service_area, so the boundary between the two read tools is not fully drawn.

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?

'Call this before recommending or booking' gives a clear usage trigger and implicitly routes booking to request_service. It never names check_service_area as the alternative for area questions, so the when-to-use guidance is clear but not exhaustive.

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