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

The annotations already declare readOnlyHint=true, and the description adds valuable behavioral context beyond that: when the limit is reached, the response indicates whether the user can pay from wallet credit or should open checkout (pay_url). This conditional behavior is transparent and consistent with the read-only annotation.

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?

The description is two sentences. The first sentence front-loads the purpose and the scoped field list, and the second adds the key conditional behavior. Every clause adds value with no redundancy.

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?

Given that an output schema exists, the description need not enumerate every return field. It covers the decision-relevant outputs and the conditional behavior at the limit, and the annotations cover the read-only safety profile. Nothing essential is missing for correct invocation.

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 has zero parameters, so the schema coverage is effectively 100% and no parameter descriptions are needed. The baseline for a 0-parameter tool is 4, and the description does not attempt to add irrelevant parameter detail.

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 clearly states the tool checks the user's publishing entitlements with a specific verb ('Check') and resource ('publishing entitlements'). It lists the exact fields returned (membership tier, slots, wallet balance, etc.), and it is easily distinguishable from sibling tools like create_listing or update_listing because it is explicitly a pre-publish, read-only check.

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 description explicitly says to use it 'BEFORE attempting to publish,' which provides a clear trigger context. It does not explicitly state when not to use it or name alternative tools, but the pre-publish instruction is strong enough to guide correct usage.

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