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

With no annotations, the description carries the behavioral burden. It usefully discloses that the retry will not create another authorization or change destinations, which is non-obvious. However, it does not explain other side effects, whether the resume is synchronous, what response is returned, or what happens if the payment is no longer retryable.

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?

A single sentence with no wasted words; the action and resource are front-loaded and the key constraint is appended without repetition.

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?

Without annotations, an output schema, or parameter descriptions, the one-sentence description leaves meaningful gaps: where relayPaymentId comes from, eligibility for retry, expected result or errors, and the relationship to get_x402_relay_status or fund_x402_relay_payment. It is enough to identify the tool but not to invoke it confidently in edge cases.

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 0% and the description does not explain either parameter. An agent can only infer that relayPaymentId identifies the payment and apiKey authenticates the caller; the description should compensate for the bare schema but does not.

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 action ('Resume') and resource ('retryable or interrupted owned x402 relay payment'), and it distinguishes the tool from creation/funding siblings by noting it does not create another authorization or change destinations. It is not a tautology and gives the agent a clear model of what this tool is for.

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 phrase 'retryable or interrupted owned' gives a clear precondition for when the tool should be invoked, and 'without creating another authorization' signals when this is the lighter-weight alternative to creating a new payment. It does not explicitly name sibling tools or say when not to use it, so it stops short of full guidance.

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