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

With no annotations, the description carries the full burden and exceeds it: it discloses destructive side effects (mismatched DMs deleted and NACK'd), one-shot retrieval semantics, the relay-draining behavior, the security model (signed DM proves ownership, raw token never stored), and post-success obligations. This is exemplary transparency.

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 and information-dense: the first sentence states the core purpose, and the critical timing warning appears immediately after. Each sentence earns its place given the protocol complexity, though 'the same token' is a minor redundancy that prevents a 5.

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 high-complexity async protocol tool, the description covers preconditions, retrieval mechanics, side effects, success return, and post-success usage obligations. An output schema exists, so return-structure details are properly delegated, and nothing critical 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?

Schema coverage is 100%, so the baseline is 3. The description adds meaning beyond the schema by explaining that dpop_token must be the exact value from request_npub_proof and that the calling application must remember it for subsequent paid calls, and by defining the lookup as the (patron_npub, dpop_token) pair. This exceeds the baseline without being redundant.

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 ('Receive npub ownership confirmation from a patron') and explicitly distinguishes itself from the credential-delivery counterpart receive_credentials. The flow context makes it unmistakably a one-shot proof retrieval, not a general receive tool.

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?

Gives an explicit precondition ('Call this only after the user confirms they have replied'), explains the failure mode if called too early, names the sibling alternative (receive_credentials), and explicitly forbids polling, looping, or retrying. This is complete when-to-use guidance.

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