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

No annotations exist, so the description carries the full burden. It discloses multiple non-obvious behaviors: calling again for the same url replaces the event list, rotates the HMAC secret, [] disables the subscription, limits to 5 urls per wallet, and charges $0.02.

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?

Four short, dense sentences with no filler. The main purpose is front-loaded, and each subsequent sentence adds a distinct fact about persistence, rotation, limits, or cost.

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 and no annotations, the description still states the return value (HMAC secret once), the idempotence/replacement semantics, the disable mechanism, per-wallet limits, and price. It leaves minor gaps such as how wallet identity is resolved or what happens on payment/billing failure, but invocation details are mostly covered by the schema.

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 the schema already documents url, events, and min_bounty_usd. The description adds useful lifecycle context like secret rotation and replacement, but it does not meaningfully extend the per-parameter semantics beyond what the schema already states.

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?

Description names the exact action (subscribe), the resource (paying wallet), and the event types pushed. It clearly distinguishes this from any list/draft/ticket/support tools in the sibling set.

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 clearly conveys when to use it: when a paying wallet needs push notifications for row.available, draft.decided, or payout.sent. It does not explicitly discuss when not to use it, but there is no obvious alternative tool among siblings, so the context is sufficiently clear.

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