Put a training plan on the calendar

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

Annotations already signal a non-read, non-idempotent mutation. The description adds meaningful behavior beyond that: it discloses the bulk side effect ('Adds many events') and the exact date mapping ('Each workout lands on start date + its plan day'), plus a precaution to confirm the plan first. This is valuable context not present in annotations.

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 sentences with no filler. The primary action is front-loaded, and the follow-up sentences add precise behavioral details and a warning. Every sentence 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?

With only 2 fully described parameters, an output schema, and annotations covering mutation/idempotency, the description is nearly complete. It covers the source (PLAN folder), the date mapping, and the bulk-event side effect. It could explicitly mention non-idempotency or what happens on repeat calls, but that is already implied by annotations and 'Adds many events.'

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 coverage is 100%, so the baseline is 3. The description adds semantic value by explaining how start_date maps to individual workouts ('start date + its plan day') and reinforcing that plan_id must reference a PLAN folder, which goes slightly beyond the schema text.

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 states a specific verb and resource: 'Copy all workouts of a training plan from the library ... onto the calendar.' It clearly distinguishes from siblings like list_workout_library (read) and create_events (individual events) by naming the PLAN folder source and the action of applying a full plan.

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 implies when to use it (to schedule a training plan) and points to list_workout_library for finding plan ids, but it does not explicitly contrast with alternatives such as create_events or duplicate_events. No when-not guidance is provided.

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