garmin_race_prediction

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

With no annotations, the description carries the burden and does so well: it discloses the data dependency (Garmin derives predictions from recent running activities) and the empty-result condition for accounts with no recent runs. It also decodes the sign convention of change_s, though it omits whether the call is read-only (implied by 'Predict') or any auth/quota details.

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 purpose, followed by the data-source caveat and then parameter detail; no filler. The Args block format is slightly verbose for a single parameter but remains scannable.

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 and no annotations, the description covers purpose, data dependency, empty-result behavior, and the sole parameter's modes. It could say more about the shape of the returned predictions (fields per distance) but is sufficient to invoke the tool correctly.

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%, so the description must compensate — and it does, explaining all three enum values and what differs between them (current-only vs. movement across a window). It even explains the semantics of an output field ('change_s is negative when the athlete got faster'), which is beyond what the schema offers.

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 opens with a specific verb and resource ('Predict finish times') and enumerates the four covered distances (5K, 10K, half, marathon). This clearly separates it from siblings like garmin_weekly_stats or garmin_personal_records, though it does not name a specific sibling it might be confused with.

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?

It explains what each period value yields ('today' = current prediction only; '90d'/'1y' = movement over the window) and warns that accounts with no recent runs return nothing. However, there is no guidance on when to choose this tool over siblings such as garmin_personal_records or garmin_training_status, so the when-to-use decision is left implicit.

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