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

Annotations already declare non-destructive, non-read-only, closed-world behavior, so the description adds the key detail that it operates on an existing workout rather than producing one. It does not say whether the original workout is mutated in place or an adapted copy is returned, nor what prerequisites exist (valid workout_id, ownership/team scoping).

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 tight, front-loaded sentences with no filler: purpose first, usage trigger second. Brevity tips toward under-specification given nine parameters, but nothing is wasted.

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 9-parameter mutation tool with zero schema description coverage, the description covers only a fraction of the customization surface and never explains how the optional parameters combine or which are required beyond workout_id. The output schema covers return values, so that gap is excused, but the input-side gaps are not.

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% across 9 parameters, so the description must compensate and largely fails: it names duration and difficulty (mapping roughly to duration_min/max and end_user_fitness_levels) and 'equipment', which is not an input parameter at all. Six parameters — locale, team_id, end_user_age, end_user_gender, user_requirements — go unexplained, and the min/max pairing of duration is never clarified.

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 ('Adapts an existing workout for a user profile') and implicitly contrasts with generation ('without generating from scratch'). It is distinguishable from create_workout/generate_workout conceptually, though no sibling is named directly.

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?

Gives a usage trigger ('when the user wants to customize a workout') and an implied exclusion (not from scratch), but never names the alternatives an agent would actually choose between, such as generate_workout, create_workout, or adapt_plan.

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