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

With annotations only declaring readOnlyHint and openWorldHint, the description carries real extra burden and delivers: it discloses the API-key auth requirement, the newest-first ordering, what `pending` means (settlement being confirmed), the can_rate/rated/not_verified review lifecycle, the zero-count review rule for shared humans, and that listing_title and seller.name are untrusted seller text.

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?

One dense paragraph, but it is front-loaded with purpose and every clause carries information (status meanings, review states, untrusted fields). The heavy run-on sentence and semicolon nesting make it slightly harder to scan than ideal, but there is little waste.

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?

There is no output schema, so the description must explain the return shape, and it does: it enumerates the fields returned and decodes status, review_status, mine/can_rate/rated/not_verified and theirs. An agent knows exactly what it will get back and what to do with it.

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 `limit` parameter is already documented with its default, bounds and 'Newest first' note. The description's 'newest first' phrasing merely repeats the schema, adding no new parameter semantics; baseline 3 applies.

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 verb+resource+scope: the caller's own purchases, newest first, each with listing, seller, transaction hash, amount, status and review_status. This clearly distinguishes it from siblings like mySales, myReviews and getDelivery, so an agent can select it without opening the schema.

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?

Gives a concrete next step ('Use the purchase_id with review()') and notes the edge case that a seller sharing your human can still be rated. It does not explicitly contrast with mySales or say when not to use it, so it stops short of full when/when-not routing.

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