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

With no annotations provided, the description carries the full behavioral burden and does so extensively: it reveals deterministic one-shot retrieval, relay draining behavior, deletion/NACK of mismatched DMs, non-disclosure of the expected phrase, and the consequence of premature invocation. It also discloses storage behavior (hash-only in vault, raw token never stored), which is material context beyond any schema.

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 description is long but dense and front-loaded: purpose first, then call condition, then exact behavior, then security/storage notes. Every sentence contributes operational or safety information, though some redundancy exists around 'same token' and the token-handling explanation. It earns its length because these details are critical for correct invocation.

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-value documentation is not the description's burden. For a stateful, one-shot, potentially destructive-flow tool, the description covers prerequisites, alternatives, failure modes, retry prohibition, security properties, and cost ('Free'). Nothing critical for correct use is missing.

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?

The input schema already documents bot parameters at 100% coverage, so the baseline is 3. The description adds real value beyond the schema by specifying that dpop_token is 'the value returned by request_npub_proof', by framing the parameter pair as (patron_npub, dpop_token), and by explaining that the returned dpop_token must be remembered for subsequent paid calls.

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 clearly states the tool's specific action: 'Receive npub ownership confirmation from a patron' and identifies it as completing the npub-OWNERSHIP-PROOF flow. It fs further disambiguates from the sibling receive_credentials by positioning this as the ownership-proof counterpart, so an agent can distinguish it without opening schemas.

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?

Explicitly states when to call: 'Call this only after the user confirms they have replied.' It names the alternative (receive_credentials), the prerequisite issuer (request_npub_proof), and gives firm anti-pattern guidance: 'Do NOT poll, loop, or retry.' This is unusually clear operational guidance.

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