Race time predictions

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

Annotations already declare readOnlyHint=true and openWorldHint=true, covering the safety profile. The description adds the specific race distances returned, which is useful context, but it does not disclose behavioral traits such as whether predictions are model estimates from current fitness data or how they update over time. The description does not contradict 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?

A single sentence that front-loads the resource and enumerates the full set of distances. Every word earns its place, with no filler or redundancy.

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 0-parameter read-only tool with an output schema present, this description is nearly complete. It could clarify whether all four distances return in a single call, but since there are no parameters, that ambiguity is minor and the output schema carries the return-value detail.

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?

The tool has zero parameters with 100% schema coverage, so the baseline is 4 and there are no inputs to document. The description appropriately focuses on what the call returns rather than inputs.

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 identifies the resource (predicted race times) and enumerates the exact scope (5K, 10K, half, full marathon). The word 'predicted' implicitly distinguishes it from garmin_personal_records, though no explicit verb is used and sibling differentiation is not stated.

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?

There is no guidance on when to use this tool versus closely related alternatives such as garmin_personal_records (actual achievements), garmin_vo2max, or garmin_training_status. With 35 siblings, the absence of any differentiation or context leaves the agent to infer usage from the name alone.

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