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

Annotations already establish that this is a non-read-only, non-destructive, closed-world write. The description adds the genuinely useful fact 'Commits immediately' — no confirmation step — plus the delivery-time semantics (past or omitted time fires now). It does not mention whether the reminder is durable or cancelable, but the key write-side behavior is disclosed.

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?

Four compact sentences, front-loaded with purpose and the immediate-commit warning, then parameter defaults and scheduling. No filler; the only mild inefficiency is that deliver_at behavior restates the schema description without adding format detail.

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 5-parameter mutation with no output schema, the description covers what an agent must know before calling: it writes immediately, defaults to self, and how to control timing. The unmentioned priority field is a minor gap rather than a blocking one.

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 40%, so the description needs to compensate and only partly does: it explains recipient_id defaulting and deliver_at past-vs-future behavior beyond the schema text. body, title, and the priority enum are never mentioned in the description, leaving the enum's intent (what 'urgent' actually changes) undocumented.

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 opens with a specific verb plus resource ('Create a reminder notification'), which separates it from task- and event-oriented siblings such as create_task or create_household_event. It stops short of explicitly naming an alternative, but the resource is unambiguous.

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?

Guidance is entirely about parameter choices (default recipient = you, omit deliver_at to fire now), not about when to pick this tool over create_task, create_routine, or create_household_event. An agent still has to infer the boundary between a 'reminder' and a scheduled task.

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