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

With no annotations, the description carries the full behavioral burden, and for a zero-parameter information tool that burden is light: it never states that the call is read-only, parameter-free, or returns static reference text rather than data. 'Read this to the person first' does add a behavioral instruction about delivery, which is more than a bare content list, but the safety/idempotency profile an agent would want is still unstated.

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 sentences: the content inventory comes first, the operational instruction second, with no filler. The list-style first sentence is slightly dense but each listed item is load-bearing, and the closing directive is front-loaded enough to steer behavior.

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?

For a no-parameter, no-output-schema reference tool, the description is largely sufficient: it says what the content covers and when to surface it. The only real gap is the lack of boundary-setting against listing_terms, which an agent could otherwise conflate with this tool.

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 is 4. The description's mention of 'every profile field it takes' actually pre-answers the reader's natural question about what fields a listing requires, adding value beyond the empty 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 enumerates exactly what the resource covers: what a listing is, cost, payment method, publisher, and the profile fields it accepts. That is a specific, scannable scope statement rather than a restatement of the name. It does not, however, differentiate itself from the overlapping sibling listing_terms, which plausibly covers pricing/terms content as well.

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 final sentence gives a genuine usage directive — 'Read this to the person first' — which tells the agent when in a flow to invoke it. But it names no alternatives (listing_terms, enquiry_describe) and gives no condition for choosing this over them, so the routing guidance is implied at best.

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