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

Annotations only cover readOnly/openWorld; the description adds substantial behavioral context: it POSTs a fixed GraphQL query, dates are validated before splicing, GraphQL errors arrive as HTTP 200 with an errors payload turned into a GarminError, and it explicitly notes that it LAGS writes. The tpType/fbtAdaptivePlanId disambiguation is genuinely useful caveat detail.

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?

Purpose is front-loaded, but the body is dense and drifts into implementation minutiae (naming the internal GraphQL query `workoutScheduleSummariesScalar`) that an agent selecting the tool does not need, and the text runs long before reaching the practical write-lag caveat.

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 usefully compensates by describing the returned rows, the scheduledWorkoutId field and its null case, and the fbtAdaptivePlanId discriminator, plus error handling. It is close to complete for a 2-param read tool, with only minor gaps.

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 100% and both parameters (startdate/enddate) are fully documented in the schema with format and UTC semantics, so the baseline of 3 applies. The description references the same startDate/endDate range but adds no syntax or format meaning beyond the 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?

States a specific verb+resource+scope: 'Every scheduled workout between two dates, as compact summaries.' The word 'summaries' and 'compact rows' implicitly distinguishes it from the full-workout siblings like get_scheduled_workouts, but it never names them explicitly, so sibling differentiation is by inference rather than direct statement.

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 range/compact-summary framing and the useful cross-reference that scheduledWorkoutId is what unscheduleWorkout consumes, but there is no explicit when-to-use-vs-alternatives guidance (e.g. versus get_scheduled_workouts or get_next_scheduled_workout).

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