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

The annotations already declare the safe read-only, non-destructive, closed-world profile. Beyond that, the description discloses what the read returns - account summary, billing state, unpaid-invoice pause status, and pay link - which is valuable because there is no output schema. It omits any auth or rate-limit behavior, but with annotations present this is acceptable.

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 tight sentences, front-loaded with the purpose and followed by the usage trigger. Every sentence earns its place, and there is no redundant restatement of the title or annotations.

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 no parameters, no output schema, and safety annotations already present, the description provides enough to invoke and interpret the tool: what it reads and when to call it. It could go slightly further by clarifying what other account details the summary contains, but the key billing-resolution information is present.

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?

This tool takes zero parameters, so the baseline is 4. The description adds no parameter meaning because there are none to explain, and the empty object schema is fully self-describing.

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 uses a specific verb and resource: 'Read the authenticated Listings API account summary and billing state'. It immediately clarifies the scope by listing the concrete data points (API pause status, pay link), which distinguishes it from sibling billing-adjacent tools like get_subscription or get_usage.

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 explicit trigger context: 'Call this after a payment_required or social_payment_required error to get the pay link again.' This is clear guidance for the primary scenario, though it does not state when not to use it or name alternative tools for checking billing state.

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