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

Annotations already cover the safety profile (readOnlyHint=true, openWorldHint=false), so the description only needs to add context — which it does by disclosing what the response contains and how to interpret the limit-reached case. It stops short of describing the pay_url handoff mechanics or whether credit balances expire, but the important behavioral signal (check before writing) is present.

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?

Front-loads the actionable instruction and follows with the field list and the limit-reached branch. Slightly dense in the middle enumerating six fields, but every item aids interpretation and nothing is redundant filler.

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 zero-parameter read with an output schema already present, this is everything an agent needs: the precondition (before publishing), the payload contents, and the decision to make on a limit-reached result. No gaps that would cause a mis-call.

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?

Zero parameters, so there is nothing for the description to disambiguate and the baseline is 4. The description wisely spends its words on return semantics instead of inventing parameter guidance.

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 (publishing entitlements) and enumerates exactly what it returns: membership tier, max vs current active listings, remaining slots, wallet credit, per-listing credit cost, and can_create_listing. That enumeration clearly separates it from the sibling listing CRUD tools, which mutate listings rather than report limits.

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?

States the timing explicitly — 'BEFORE attempting to publish' — which is the exact condition an agent needs to gate a create_listing call. It also names the downstream branch: pay from wallet credit or open checkout via pay_url when the limit is reached.

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