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

With no annotations, the description carries the full burden and does so well: it discloses the operator/proof authorization requirement, atomic all-or-nothing claim before sats move, idempotency via the shared primary key ('a second press collides on the key'), and failure semantics (legs marked failed, debt returns, attempt stays on record). This is unusually rich behavioral disclosure for a mutation tool.

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?

The purpose is front-loaded and the atomicity/idempotency content is substantive, but the prose is padded with narrative flourishes ('which is the shape this always needed', 'the two cannot pay the same match twice') that lengthen it without adding callable detail.

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?

An output schema exists so return values need not be described, and the description covers prerequisites, atomicity, idempotency, and failure recovery. Only the undocumented dpop_token parameter leaves a real gap.

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 only 50% (npub documented, dpop_token not), so the description is expected to compensate, but it never mentions either parameter by name or explains their formats. The closest reference is 'the caller to be the operator, proven', which only loosely gestures at the dpop_token's role.

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 opening sentence states a specific verb and resource ('pay everything owed to the charity, in one Lightning payment') and implicitly contrasts with per-match `pay_out` later in the description. An agent can distinguish it from `pay_out`/`payout`/`set_charity` from the text, though it never names those siblings as alternatives directly.

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 clear context for when the batch form is the right choice ('a single match's share can be smaller than the fee floor ... paying per match can cost more than it delivers') and states the operator-only prerequisite. It stops short of an explicit 'do not use this when X' exclusion.

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