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

With no annotations provided, the description carries the full burden of behavioral disclosure. It openly states that no Authority npub is required or consulted, that a cryptographic challenge is issued, that the nsec never leaves the device, and that the challenge expires in 10 minutes. This is rich context beyond simple 'returns a challenge.' It also describes the patronage identity side effect.

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 several sentences long but each adds value: it defines the flow, disambiguates from the operator path, explains security, and lists return values. It is front-loaded with the primary action and logically structured. Slightly long for a simple registration tool, but appropriately detailed given the security-sensitive nature.

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?

The description covers the full context: actor, target, flow, security mechanism, next step, and timeout. It explains the return values even though an output schema exists, which is helpful. The only aspect not covered is the exact behavior of confirm_citizenship, but that's a separate tool. For this tool's scope, it is complete.

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 has 0% description coverage, so the description must compensate. It explains that 'npub' becomes the patronage identity, but it does not explain the 'display_name' parameter at all. The parameter names are self-explanatory, but with only two required parameters and no schema descriptions, the lack of any mention of display_name's intended usage or constraints leaves a gap.

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 action: 'Begin the citizen registration process (Operator-owned flow).' It identifies the specific resource (patron npub registered as Citizen in the DPYC community) and distinguishes it from operator registration, which is a separate sibling flow. The verb 'Begin' and the explicit naming of the citizen path make the tool's purpose unambiguous.

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 explicitly states when to use this tool: 'Called by the Operator on behalf of a patron' and provides an exclusion: 'Not to be confused with operator registration, which goes through the Authority via a Nostr DM delegation request.' It also mentions the next step (confirm_citizenship) and a 10-minute validity window, giving clear operational guidance.

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