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

Annotations already declare readOnlyHint=true, and the description reinforces this with 'Read-only, no side effects.' It adds non-obvious behavioral context beyond annotations: products.create consumes 2 credits per call, payment/shipment configuration is a prerequisite, and the tool reveals plan-based limits. This gives an agent useful operational expectations without contradicting the annotations.

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 dense but every sentence earns its place: the first states the core purpose and specifics, the second provides actionable sequencing and dependency information, and the final sentence confirms safety. It is front-loaded with the result and then explains why and when to invoke the tool.

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 there are no parameters and an output schema exists, the description covers all the essential context an agent needs: what the tool reports, why it matters, when to call it, and that it is safe. It even ties the result to downstream behavior with products.create, making the tool's role in the workflow fully understandable.

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 input schema has zero parameters, and the description correctly focuses on what the response contains rather than input semantics. It names the key result fields—listing capabilities, payment/shipment setup, max images/price, AI credit balance—which adds meaning beyond the empty schema. The baseline of 4 for a parameterless tool is appropriate.

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 states a specific verb and resource: 'Returns the authenticated user's current listing capabilities.' It enumerates exactly what is included—creation eligibility, payment/shipment configuration, plan limits, and AI credit balance—so an agent can distinguish this from generic seller info tools like sellers.get.

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 gives explicit timing guidance: 'Call this BEFORE asking the user for photos or calling products.create.' It explains why the preflight matters by noting that payment/shipment methods are required for products.create to succeed. It does not explicitly contrast sellers.status with alternatives like sellers.get or products.get, so it stops short of full when-not-to-use guidance.

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