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

Adds substantial detail beyond the annotations: the link lives 7 days, the human must tick a waiver checkbox, payment happens on Stripe in USD, and the machine url expires in about 30 minutes. This complements the openWorldHint/non-idempotent hints with concrete lifecycle behavior without contradicting them.

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?

Front-loaded with the primary action and tightly worded, but the telegraphic run-on style ('...set for_agent_wallet: true to also get url...') requires re-reading to parse the conditional branch cleanly.

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 still names the key return values (pay_link, url) and the completion path (poll top_up_status), so an agent knows what it gets back. Minor gap: it doesn't state where pay_link appears in the response, but the necessary flow is covered.

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 coverage is 100%, so all three params are already documented. The description reinforces the for_agent_wallet meaning ('machine payment', 'never give url to a human') but adds little new syntax, and does not mention the amount_cents enum, leaving that to the schema.

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?

States a specific verb and resource: 'Create a payment link to fund your balance.' It immediately distinguishes the two distinct flows (human pay_link vs machine for_agent_wallet url), so an agent can tell exactly what the tool produces.

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?

Explicit routing: 'Humans always use pay_link' vs 'Only for a machine payment by your own agent wallet set for_agent_wallet: true'. It also names the follow-up sibling tool ('Then poll top_up_status'), converting a two-step flow into unambiguous instructions.

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