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

Annotations already declare readOnlyHint, idempotentHint, non-destructive and closed-world, so the safety profile is fully covered and the description need not repeat it. The description adds the practical behavior of what it returns and the hand-off to check_readiness, which is useful, but it doesn't address pagination, ordering, or how the challenge list is scoped beyond sport.

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, no filler, and the core action is front-loaded before the check_readiness hand-off. Slightly compressed phrasing ('the furthest a person has run, ridden or swum') costs a little readability but the structure is efficient.

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 appropriately explains what comes back (the first training question and every challenge in the sport) and what the caller does next. For a read-only query with fully documented parameters, this is nearly complete; it could still clarify what identifying inputs the tool has already or how results are ordered.

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 the schema documents sport (with enum), furthest_km, and the optional challenge_id in detail. The description only loosely gestures at the input ('the furthest a person has run, ridden or swum') and says nothing about challenge_id, so it neither adds nor detracts much beyond the schema baseline of 3.

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 action: it takes the furthest distance per sport and returns the first training question plus all challenges in that sport. It clearly separates itself from the sibling check_readiness by naming it. The only ambiguity is the somewhat vague phrase 'the first question about their training', but the operation and result are recognizable.

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 sketches a workflow: this tool surfaces the questions and the challenge list, then 'check_readiness picks the challenge once the questions are answered'. This gives the agent a clear sense of when this tool is the entry point versus the follow-up. It doesn't cover other siblings like add_challenge or ladder, so it stops short of full when/when-not guidance.

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