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

Annotations already declare readOnlyHint and idempotentHint, and the description adds context those annotations cannot carry: the 404-when-disabled behavior, the billing read scope requirement, and the 403 claim gate. This is exactly the kind of auth and failure-mode disclosure that earns credit beyond structured fields.

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 dense sentences, front-loaded with the return shape and then the operational constraints. The enumeration of transfer statuses is slightly long, but it substitutes for a missing output schema, so the length mostly earns its place.

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 output schema, the description takes on the burden of describing return values and does so thoroughly (status values, attempts, last error, next retry, Stripe id, idempotency key). Combined with the auth and availability notes, nothing an agent needs to call it correctly is missing.

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 description coverage is 100% and the single run_id parameter is already documented as a UUID from a list_payout_runs or request_payout_run result. The prose adds no syntax or format detail beyond that, so the baseline 3 applies.

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 ('Read one payout run with its Stripe transfers') and enumerates the fields returned, so an agent can tell it apart from list_payout_runs without opening either 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 explicitly states when the tool is unavailable (404 while payout runs are off, 403 with an unclaimed sandbox key), how to check availability via list_payout_runs' execution.enabled, and the required scope. That is the full when/when-not/alternative picture.

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