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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description adds real context beyond that: the 24-hour window, the empty-state behavior ('Returns a note when nothing rang'), and the richness of the returned scoring data (order, times from the ring, snoozes, titles, still-asleep).

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 core purpose and scope are front-loaded in the first clause, and every sentence contributes (what's shown, when it applies, what it accepts, empty-state). The second sentence is a dense run-on combining usage, parameters and return content, which costs a little readability.

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 carries the return-value burden and does so: it enumerates the wake-order fields, titles, snooze info, still-asleep status, and the no-data note. Combined with the single optional parameter and full annotation coverage, an agent has everything needed to call it correctly.

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% and the id parameter's description already states that its absence means every alarm from the last 24 hours. The description restates that same semantics ('One alarm by id, or every alarm that rang... in the last 24 hours') without adding format or syntax detail, which is the expected baseline when the schema does the work.

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+resource: showing the wake-order leaderboard for alarms that already rang, including times, snoozes and titles. This is clearly distinct from siblings like show_alarm (single alarm detail) or list_my_alarms (scheduling), so an agent can select it without opening the schema.

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?

Explicitly scopes the tool to alarms that already rang and redirects future-alarm information ('when an alarm rings next is on its card and in the alarm list'). It also explains the two retrieval modes (single id vs. last-24-hours sweep), though it doesn't name a specific sibling tool as the alternative.

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