preview_workout

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

Annotations already state readOnlyHint=true and openWorldHint=false, and the description reinforces this with concrete operational detail: no API call, nothing written. It also discloses decomposition behavior (expands repeats, sums planned duration and distance, counts steps with targets and open-ended steps), which tells the agent what the output reflects. It does not cover error/edge behavior, but it adds meaningful context beyond the 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?

It is front-loaded: the first sentence states the action, its purpose, and its side-effect-free nature, and the second supplies the computed details a caller cares about. Two dense sentences with no filler; the only mild cost is the density of the second sentence.

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 zero-side-effect preview tool with no output schema, the description covers the necessary ground: what is rendered, that nothing is written, what is computed (totals, step counts), and the related write/validate tools. Only error or empty/invalid-document behavior is left unstated, a minor gap.

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%, so all four parameters are already documented in the schema. The description mentions the workout document and output format indirectly (workout text vs. json machine-readable), but adds no syntax, constraints, or format meaning beyond what the schema provides. Baseline 3 applies when the schema does the heavy lifting.

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 gives a specific verb+resource (render the drafted workout document as Intervals.icu workout text with totals) and explicitly frames it as a preview before writing, distinguishing it from the sibling "add_or_update_event" (the write) and "validate_workout" (the check list). An agent can tell exactly what this produces without opening the schema.

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?

"Use to show the athlete how a drafted workout will look before writing it" gives a clear when-to-use condition, and it points to "add_or_update_event" as the write path and "validate_workout" for the full check list. It stops short of naming a when-not-to-use or routing between other siblings such as compare_workouts or get_workout_library, so it is clear context without full exclusion logic.

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