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

Annotations cover the safety profile (readOnlyHint=false, destructiveHint=false, openWorldHint=true), and the description goes further by disclosing the internal multi-call resolution chain, the specific endpoints used, and that it throws when no workouts exist. It stops short of describing the final POST's side effects or error surface, so not a 5.

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?

Front-loaded with the core action and defaults, then a compact sentence describing the resolution sequence. Dense but every clause carries information; only the endpoint path detail is arguably more than an agent needs.

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 no output schema, the description still conveys the side-effecting nature of the call, the fallback resolutions, and the failure mode (throws when no workout exists). Annotations already cover the read/destructive/open-world profile, so the remaining gap is only in the response format, which is minor.

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% and both parameters are trivially described as 'Numeric id', so the baseline would be 3. The description adds genuine meaning: it explains that a missing deviceId is resolved via mylastused's userDeviceId and a missing workoutId via getWorkouts(0,1), turning two opaque optional ids into self-resolving arguments.

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 and resource ('Sends a workout to a device') and immediately specifies the default operand selection, which is the key behavioral fact for this tool. It does not name sibling tools like download_workout or get_workout_by_id, so the differentiation from related read/push tools is left to inference, keeping it below a 5.

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 communicates that both parameters are optional and what happens when they are omitted (newest workout, most recently used device), which implies when the tool can be called bare. However, it never states prerequisites (e.g., that the user must have a paired device) nor contrasts the call with alternatives such as preview_workout or schedule_workout.

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