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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the trailing 'Read-only' is largely redundant. The description still adds value annotations cannot: the inclusion/exclusion rules (checkin follow-ups shown, active drill omitted) and the shape of each returned entry.

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?

Sentences are front-loaded: scope first, then usage trigger, then exclusions. The only waste is the final 'Read-only.' sentence, which restates annotations, and the parenthetical examples are slightly dense but informative rather than padding.

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 no output schema and no parameters, the description carries the return-value burden itself and does so by naming the fields per entry (id, subject, next occurrence) and the categories covered. Combined with rich annotations, an agent has everything needed to call this correctly.

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?

The tool takes zero parameters, so per calibration the baseline is 4; there is nothing for the description to disambiguate. It correctly adds no parameter narrative and uses the space for return-shape and scope instead.

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 uses a specific verb ('List') and enumerates exactly what is returned: reminders, watches (tournament result, weekly ranking position, price drop) and routines, each with id, subject and next occurrence. This is concrete enough that an agent can distinguish it from siblings like get_drill_digest or get_tournament_calendar without opening a 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?

It states a clear trigger ('when they ask what Morris will send them') and a workflow hook ('before cancel_reminder'), plus boundary conditions (Morris follow-ups appear as checkin; the active drill is not listed). It stops short of routing the agent to a specific alternative tool for the drill case, so it is strong but not exhaustive.

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