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

Annotations already cover the safety profile (readOnlyHint=true, openWorldHint=true), and the description adds genuine contract detail beyond them: month is 1-12 on input but converted to 0-indexed on the wire, and year>=2000 is validated. That input-normalization quirk is exactly the kind of thing an agent would otherwise get wrong. It does not describe the response shape beyond 'and more'.

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?

Short and front-loaded, but the 'month is 1-12' fact is stated twice within two sentences ('`month` is 1-12' and 'validates ... `month` 1-12'), which is visible waste in a description this size. The remaining content is dense and earns its place.

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 no output schema, the description covers inputs well but leaves the return shape vague ('and more') and says nothing about ordering, event types, or pagination. Since there is no output schema to fall back on, more return-side detail would have been warranted.

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 carries the burden for both parameters. It fully documents month (1-12, converted to 0-indexed internally) but leaves year only constrained to >=2000, with no format guidance (4-digit? string vs integer?). Partial compensation for a two-parameter, zero-coverage schema.

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 the resource and its scope precisely: 'The calendar for one month... scheduled workouts, events and more.' An agent can tell this is a month-scoped calendar reader rather than a single-workout lookup. It stops short of naming the adjacent siblings (get_next_scheduled_workout, get_scheduled_workout_summaries, list_calendar_events), so it does not fully differentiate on its own.

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 by the month scoping — call this when you need a whole month's calendar rather than a specific workout. There is no explicit statement of when to prefer this over get_scheduled_workout_by_id, get_next_scheduled_workout, or get_scheduled_workout_summaries, leaving the choice to inference.

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