Menstrual cycle

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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and openWorldHint=true, so the safety profile is covered. The description adds the useful caveat that results only exist when the cycle is tracked in Garmin Connect, but says nothing about the return shape.

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?

A single efficient sentence with the data-availability condition front and center. It is not padded, though it is arguably too sparse to be fully useful.

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?

There is no output schema, so the description carries the burden of explaining what a caller receives, and it does not — it never states whether the response is a cycle phase, predicted dates, or logged symptoms. For a tool whose return value is entirely undocumented elsewhere, this is a notable gap.

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?

With a single parameter at 100% schema description coverage, the schema already documents the YYYY-MM-DD format and today-default. The description adds no additional meaning about the date parameter, 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?

Names the resource (menstrual cycle tracking) and the data source (Garmin Connect), but uses a nominal phrase 'Cycle tracking' rather than a clear verb and never says what data is returned (phase, predictions, symptoms). An agent can guess it fetches cycle info for a date, but the purpose is only implied.

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?

The clause 'if it's tracked in Garmin Connect' hints at a data-availability precondition, but there is no guidance on when to call this versus the many other daily-metric siblings, nor what to do when no cycle is tracked.

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