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

Annotations already declare readOnly, idempotent and non-destructive, so the safety profile is covered. The description adds genuinely non-obvious context: the call is scoped to the caller's own reminders and, unexpectedly for a read operation, requires the alerts:write scope — a detail an agent could otherwise get wrong.

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 short sentences, zero filler, with the scoping constraint and return content front-loaded before the prerequisite. Nothing is repeated from the title or annotations.

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 covering return values, rich annotations, and no parameters, the description supplies the remaining critical facts: personal scope and the required alerts:write scope. Only ordering/volume expectations are left unstated, which is minor for a list tool.

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 and schema coverage is 100%, so there is nothing for the description to disambiguate. Baseline for a parameterless tool would be higher, but the description also volunteers no argument or scoping options, so it neither adds nor subtracts meaning here.

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 and resource ('List ... your reminders') and adds scope ('only your'), which separates it from list_alerts and the mutation siblings set_reminder/delete_reminder. It stops short of naming a sibling explicitly, so it is clear but not maximally differentiated.

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?

Usage is implied rather than stated: an agent can infer this is the read path for reminders versus set_reminder/delete_reminder. There is no explicit when-not guidance, no mention of list_alerts as the alternative for alert objects, and no note on whether filtering or pagination applies.

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