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

With no annotations, the description carries the disclosure burden and largely meets it: it reveals the invite is 'single-use', states the returned artifacts (deep links + QR code), and describes the binding side effect ('challenger taps... to bind their messenger identity to the config'). It does not detail persistence, failure modes, or whether existing invites are invalidated.

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 in the first sentence, followed by a compact return/flow sentence and a separated ACCESS note. No filler; every sentence contributes actionable information.

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 2-parameter tool with no output schema, the description explains what is returned and why, and gives auth/usage context. It falls short of full completeness by not specifying the response shape (property names for the links/QR) or error/precondition behavior such as whether challenger_id must already exist.

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?

Input schema descriptions already cover both parameters completely ('HITL config ID', 'Challenger ID to invite'), so the baseline is 3. The description's references to 'the config' and 'challenger' add narrative context, but no new semantic meaning beyond the schema.

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 opens with 'Mint a single-use Proof-Me enrollment invite for a challenger' – a specific verb and target resource. It also states the deliverables ('Telegram + WhatsApp deep links and a QR code'), and the 'start_login does NOT open this tool' note helps distinguish the tool from a sibling flow.

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 ACCESS block gives explicit prerequisites and a call sequence: 'needs a Proof account', 'Authenticate this client ... then call this tool again'. It also supplies a when-not instruction ('start_login does NOT open this tool'), though it does not contrast with add_challenger or other challenger-management alternatives.

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