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

Annotations only declare that this is a non-read-only, non-destructive, closed-world write. The description adds real context beyond that: the reminder surfaces under Later in Needs you, fires a notification with a SkipCalls chat ready to continue, and returns the reminder id plus fire time. It stops short of saying whether the chat is created at schedule time or fire time, which is the one behavior an agent might still guess at.

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 sentences, each doing distinct work: trigger, placement/notification behavior, return value, and sibling routing. Front-loaded with the trigger phrase. Slightly dense with three sibling references in one sentence, but nothing 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 5-required-param mutation with no output schema, the description covers the missing return-value information (id and fire time) and the user-visible effect of the call. Annotations carry the safety profile and the schema carries the parameters, so nothing an agent needs is absent.

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 every parameter is already documented in detail (including the null semantics for note and contactId, and the 9 PM–8 AM rule for timeNamed). The description adds only "at the given time" and does not enrich any parameter beyond the schema, so the 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 ("Create a reminder") plus the triggering user phrasing "remind me …", so an agent can match intent directly. It also distinguishes itself from create_contact_note, cancel_reminder, and update_work by name.

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 explicit when-to-use (user says "remind me"), explicit when-not alternatives for two adjacent needs: cancellation routes to cancel_reminder, rescheduling to update_work (action later), and a note that should stay on a customer record routes to create_contact_note instead.

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