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

The annotations already declare readOnly/idempotent/non-destructive, so the safety profile is covered. The description adds real value beyond them: the fields returned (name, creator, ring time, riders, hearts, link), the page limits ('Up to 25, 10 when not given'), and the empty-result note ('Returns a note when none match') — helpful behavioral detail for a tool with no output schema.

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?

Dense and front-loaded, leading with what it lists before the qualifiers. The colon-heavy sentence is slightly awkward to parse but no sentence is wasted.

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 read-only, no-output-schema list tool, the description covers result shape, limits, ordering, and the empty-result case, and its annotations carry the safety profile. Nothing essential for correct invocation is missing, though it could note whether results are paginated.

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%, so the schema already documents kind, sort, limit, and search. The description restates those semantics in prose ('newest or most joined first,' 'optionally matching words or of one kind,' 'Up to 25, 10 when not given') but adds no syntax or format detail beyond what the schema provides — 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 ('Lists public alarms anyone can join') with clear scope (public, joinable by anyone). It also distinguishes itself from the sibling list_my_alarms by noting 'the person's own alarms are a separate list,' so an agent can tell the two apart without reading either 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 usage to 'public alarms by anyone' and points to the separate own-alarms list as the alternative, which routes the agent correctly. It stops short of a full when-to-use/when-not framing, but the context is clear.

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