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

Annotations already declare readOnlyHint and openWorldHint, so the safety profile is covered, and the description adds genuinely new behavior: a hard cap of the first 20 results plus a total count, a default limit, and the charging model ($0.002 USDC per successful call via x402, failed calls free). The payment and result-truncation details are exactly the kind of context annotations cannot carry; only the omission of rate-limit or error behavior keeps it from a 5.

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 core capability and result cap are stated first, followed by the regionId rule, siblings, and price in a logical order with no filler sentences. The field enumeration and sibling blurbs make the first sentence long, but each clause carries information an agent would otherwise have to infer.

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 an output schema present the description does not need to explain return structure, yet it still summarizes the payload and the 20-result cap, and it covers scoping, defaults, alternatives, and cost. The only gap is that it never clarifies whether the 20-result cap can be raised beyond the limit parameter's own 1-20 range, which is implied but not stated.

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 100%, so all three parameters are already documented in the schema, including the regionId examples that the description repeats. The description adds only marginal meaning beyond the schema, namely that omitting regionId defaults to a US-wide search, so the baseline 3 is appropriate.

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 a specific resource (Booksy beauty/barber/wellness businesses), the scoping dimensions (category and region), and enumerates the returned fields (address, coordinates, rating, socials, services with price/duration). It also explicitly disambiguates against two siblings, b2b_bbb and b2b_bizquest, so an agent can tell exactly what this tool is and is not.

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?

It gives concrete when-to-use routing for two alternatives and explains the regionId tradeoff (omit it and the search is US-wide), which is a real usage decision an agent must make. It falls short of full coverage in a server with dozens of overlapping business-directory siblings (e.g. google_maps, yellowpages, manta) that are never mentioned as alternatives or exclusions.

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