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

Annotations already convey read-only and non-destructive behavior, so the bar is lower. The description adds the non-obvious default time window rule, which is useful, but it does not disclose how include_completed affects results or how explicit dates behave.

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, front-loaded with the action and resource, with no filler. Every phrase adds meaning.

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 read-only tool with three optional, self-describing parameters and an existing output schema, the description covers the main behavior and default range. The main gap is the unstated semantics of include_completed, but the schema title and default mitigate the ambiguity.

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 0%, so the description needed to compensate, but it only clarifies that absent dates default to the next 14 days. It never explains include_completed or the expected date format, leaving the agent to rely on property titles and defaults.

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 names a clear verb and resource: 'Get scheduled workouts and calendar events.' This distinguishes the tool from siblings like get_activity, list_daily_metrics, and get_custom_metrics, and the parenthetical examples clarify what counts as a calendar event.

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 description gives clear usage context by stating the default behavior ('Defaults to the next 14 days'), which tells an agent when a plain call is appropriate. It does not explicitly name alternatives or exclusions, but the purpose is specific enough that overlap with siblings is minimal.

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