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

Annotations already declare readOnlyHint=false, destructiveHint=false, and idempotentHint=false, so the safety profile is covered. The description adds recurrence scope (one-time/weekly/monthly/yearly), but says nothing about the approval_id single-use requirement present in the schema or about duplicate-creation risk despite idempotentHint=false.

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?

Two tight sentences, front-loaded with the use case and followed by supported recurrence modes; no filler. The second sentence largely restates the frequency_type enum, so there is minor redundancy.

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 an output schema present, return-value explanation isn't required, and 100% schema coverage covers parameters. The main unmet need is behavioral: this is a non-idempotent write with an approval_id parameter, and the description never addresses approval or duplicate behavior.

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 schema documents all five parameters, so the baseline is 3. The description adds only the framing that the reminder is 'about a person' (clarifying contact_id) and echoes the recurrence values already enumerated in frequency_type.

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 description conveys a create operation for a contact-linked reminder with recurrence, using the user-intent framing 'when the user wants a nudge about a person on a schedule.' It distinguishes itself from reminders.get/list/update/delete by conveying creation, though the verb 'create' is implied rather than stated.

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 clear trigger condition (user wants a recurring nudge about a person) plus the example utterance, which tells the agent when to reach for this tool. It stops short of naming alternatives or exclusions, e.g. vs tasks.create for non-person tasks.

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