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

Annotations already declare readOnly, idempotent, non-destructive and open-world behavior. The description adds real context beyond those structured fields: the required listings:read scope, the pagination contract (nextCursor continues; null terminates), and the failure mode where an invalid or expired token forces sign-in again. Return-format details are carried by the output schema, so this is solid but not exhaustive.

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?

Three tight sentences, each earning its place: what it returns, the pagination contract, and the auth failure mode. The purpose and usage cue are front-loaded before the operational details.

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 annotations covering the safety profile and an output schema covering returned fields, the description only needs to add auth scope and paging semantics, and it does both. An agent has everything required to call this correctly on the first attempt.

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%, so the baseline is 3, and the description modestly exceeds it by explaining the paging loop: pass nextCursor to continue and a null value ends the list. That terminal condition is not spelled out in the schema's cursor property, which only says to use the previous response's nextCursor.

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 verb (Find/List), the exact resource (the authenticated Builder's drafts and live listings), and scopes it to owned listings. It also distinguishes itself from the create path by framing the call as a pre-step 'before creating another draft', so an agent can separate it from z2h_create_draft_listing and z2h_get_listing without opening a 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?

It gives a clear situational cue (check existing drafts/live listings before drafting another) that routes the agent away from the write sibling. However, it never explicitly names the alternatives (z2h_get_listing for a single listing, z2h_search_marketplace/z2h_compare_marketplace_listings for non-owned inventory), so the when-not condition is implied rather than stated.

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