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

With no annotations, the description carries the full burden and does substantial work: minimum 10 sats, no platform fee with routing fee at cost, unused routing reserve refunded, operator-key auth requirement, and a post-key-rotation cooldown. Missing pieces are failure semantics (insufficient balance behavior) and whether the payout is immediate/irreversible.

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?

One front-loaded sentence plus a parenthetical of dense, high-value constraints and an auth/cooldown note. Slightly packed, but every clause (fees, minimum, refund, auth, cooldown) 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?

For a one-parameter fund-moving tool with no annotations and no output schema, the description covers the cost model, minimum, authorization requirement, and timing constraint. It would be complete with a brief note on failure/insufficient-balance behavior or what a successful call returns.

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?

There is a single parameter with 100% schema coverage, so the schema already documents invoice as a BOLT11 string. The description adds relevant constraint context (minimum 10 sats, external invoice target), which slightly exceeds the schema baseline.

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 (withdraw) and resource scope (funds from the operator account to an external Lightning invoice), which separates it from agent-wallet tools like pay_invoice or fund_agent. It doesn't explicitly name those siblings, so an agent still has to infer that this is the operator-payout path rather than a general payment path.

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?

Usage is implied rather than stated: 'from the operator account' plus 'REQUIRES OPERATOR KEY' signals this is the operator-withdrawal path, and a cooldown implies rate-limited use. There's no explicit when-to-use/when-not guidance and no naming of alternatives such as create_withdraw_link, claim_lnurl_withdraw, or pay_invoice.

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