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

Annotations already cover read-only, idempotent, non-destructive, closed-world behavior, so the bar is lower, and the description still adds real context: results are 'cited' (provenance/evidence attached) and an empty answer means 'no signals found', not 'seller is bad'. That negative-result caveat is exactly the kind of disclosure annotations cannot express. It omits ambiguity handling and any rate/source limitations.

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?

Two tight sentences with no filler, and the core deliverable is front-loaded before the sibling comparison. Slightly compressed to the point of being cryptic in the opening clause, but nothing is wasted.

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?

An output schema exists and annotations cover the safety profile, so the description only needs to characterize the result and its interpretation, which it does: cited signals or a plain no-signals statement, with the negative-finding caveat. Nothing an agent needs to select and call it correctly is missing.

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 0% and the only param is an unlabeled 'name' string, so the description carries the burden. It does add meaning by saying the value may be a seller OR a brand name, which the schema does not convey. It gives no format, casing, or example guidance, so compensation is partial.

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?

Names a specific resource (cited ownership signals for a seller/brand) and explicitly frames it as the same data as lookup_brand re-phrased for a seller, which lets an agent separate it from that sibling. The phrase 'cited ownership signals' is somewhat jargon-y and never unpacked, so the exact payload is only partially clear.

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 use condition ('for a seller you are about to buy from') and points at lookup_brand as the related tool with the same data. The parenthetical '(not a negative finding)' is genuinely useful interpretive guidance about how to read an empty result. It stops short of stating when NOT to use it, or how to choose between this and lookup_brand when the input is ambiguous (a name could be both).

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