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

Annotations only declare the generic write/openWorld/idempotent profile; the description adds the substantive behavioral facts: a per-owner-per-day rate cap, the unconfirmed-address precondition, and the auth requirement (OAuth sign-in or passport-key signature) plus the refusal mode 'signature_required' when a plain token is used. This is exactly the beyond-annotation context the dimension rewards.

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?

Purpose and precondition are front-loaded and every clause carries information (rate limit, auth, refusal, HTTP alternative). It is dense and parenthetical-heavy, verging on run-on, but no sentence is filler.

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?

With no output schema, the description still covers the key operational facts an agent needs: preconditions, rate limit, auth requirements, and the failure mode name. It could specify what a successful response looks like, but for a single-purpose trigger tool it is otherwise 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?

Schema description coverage is 100% and there is only one optional parameter, so the schema already documents passport_token fully. The description adds only incidental context ('header or passport_token') and does not clarify syntax or default behavior beyond it, so the baseline 3 applies.

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 ('Send your owner the one-time confirmation email now') and immediately scopes it with the consequence of inaction ('until they press Confirm... emails from your utilities do not reach them'). This lets an agent distinguish it from email-producing siblings like ask_human, alerts, or reminders.

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 explicit when-to-use and when-not-to-use conditions: only while the address is unconfirmed, at most once per owner per day, and never after the owner has stopped emails. These exclusions are the alternatives guidance an agent needs.

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