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

Annotations only supply the safety profile (readOnlyHint=false, destructiveHint=false, openWorldHint=true), and the description goes materially beyond that: it discloses the privacy design, that saved searches are deliberately not listed in chat, that the email contains a passwordless login link, and that alert emails carry a per-alert unsubscribe link. The one notable omission is that repeated calls presumably send repeated emails (consistent with idempotentHint=false), which is not stated.

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 is front-loaded and the privacy rationale follows logically, ending with a concrete agent directive ('Tell them to check their email'). There is mild redundancy between the first sentence and 'where they can change or delete each one', but nothing that wastes an agent's attention.

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 low-parameter, side-effecting tool with an output schema and annotations present, the description covers the essentials: what happens, why, and what the agent should tell the person. Missing pieces are the email-language parameter and any note about duplicate sends, both minor against the overall coverage.

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 description adds essentially no parameter meaning. The required 'email' is only obliquely implied by 'emails the person', and the 'language' parameter — which evidently controls the language of the outgoing email — is never mentioned anywhere, despite schema description coverage sitting at 50%. With half the parameters undocumented in the schema, the description should have compensated and does not.

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 first sentence names a specific verb set and resource ('see, change or delete their saved searches and email alerts'), and the following sentences make clear the tool's actual mechanism is sending a login link by email rather than listing or mutating anything directly. That distinguishes it from siblings like save_search. It stops short of a 5 because the opening framing ('Let a person see, change or delete') slightly undersells that the call's real effect is an email dispatch.

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?

Usage is implied: use this when someone wants to view, edit or remove saved searches or alert subscriptions, and the agent is told to instruct the person to check their email. There is no explicit contrast with save_search (the create-side sibling) and no stated preconditions beyond the email address. Adequate but leaves the alternative unaddressed.

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