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

Annotations only indicate readOnlyHint=false and openWorldHint=true. The description enriches this substantially: it explains the rating check semantics (unrated buyers pass), the effect on the hosted buy link (refusal with forbidden and details.reason), that declines are not reviews, defaults off, reply is the listing's bar, and the untrusted field being empty. This goes far beyond the annotations, covering edge cases and the tool's operational behavior.

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 dense but every sentence serves a purpose: purpose, parameter semantics, behavioral consequences, and reply format are all covered. The use of backticks for terms improves readability. It is longer than minimal but not wasteful, and it front-loads the core purpose before diving into parameter nuances.

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?

Without an output schema, the description must explain the reply, which it does ('Reply: the listing's bar'). It also covers the refusal behavior, the idempotency key indirectly via schema (though the description doesn't mention it, the schema covers it). Given the tool's complexity—rating thresholds, review counts, edge cases—the description is complete enough for an agent to call it correctly without additional context.

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 already documents min_stars and min_reviews, but the description adds crucial nuance: 'no stars is not zero stars' clarifies unrated buyers pass, and it explicitly distinguishes min_reviews as the buyer's received-review count versus search's distinct-buyer count. It also notes the reply content. With 75% schema coverage, the description compensates for the remaining gaps (e.g., listing_id is self-explanatory) and adds value beyond the schema.

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 opens with a clear statement of function: 'Only accept buyers at or above a rating on one of your listings' — a specific verb (accept/set) and resource (listing). It also identifies the actor constraint ('only the owner may') and states the effect on the hosted buy link. This clearly distinguishes it from sibling tools like setWebhook or setHumanEmail by focusing on buyer rating thresholds.

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 context on when to use the tool (settings for a listing's buyer acceptance) and prerequisites (API key, owner-only). However, it does not explicitly contrast with alternative tools that might achieve similar outcomes, nor does it state when not to use it. It does clarify the distinction between this tool's min_reviews and search's same-named filter, which is useful but not about usage alternatives.

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