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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive), so the description's value is in the behavioral detail it adds: default status filtering, time-ordered results, newest-first notification ordering, and the 24-hour window. It also discloses an extra return payload (current server time and user timezone) not visible anywhere else. It does not discuss limit/truncation behavior when results exceed the cap.

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?

Three tight sentences with the default scope and ordering front-loaded, then the optional branch, then the return payload. Every clause carries information, though the parenthetical '(scheduled/snoozed) ones unless status is given' is compressed at the cost of 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?

No output schema exists, yet the description compensates by naming the extra non-alarm payload (server time, timezone) an agent needs for scheduling decisions. For a five-optional-parameter read tool with full schema coverage, nothing required to call it correctly is missing.

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%, so every parameter including the status enum and default is already documented in structured form. The description's mentions of the default status set and include_notifications largely restate the schema, adding only the rationale for deduplicating notifications. Baseline 3 is appropriate when the schema carries the parameter semantics.

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 (list the user's reminders) plus the ordering and the default filter scope (active/scheduled/snoozed unless status is given). The optional include_notifications branch is described precisely as notifications from the last 24 hours, newest first. Against siblings like create_alarm, update_alarm and cancel_alarm, the read-only listing role is unmistakable.

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 a concrete usage driver: enable include_notifications 'so you do not send the same one twice', which tells the agent when that flag matters. It also defines the default call shape (active alarms only). It does not explicitly name when to prefer a sibling or when not to call this tool, so it stops short of full guidance.

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