getActivityLaps

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

With no annotations, the description carries the full burden and does substantial work: it discloses the data provenance (.FIT file), the output granularity (one row per lap), the generation modes (manual, auto-lap per km, workout step), and the units/interpretation of each metric. It does not mention whether the activity must be fully synced, authorization scope, or what happens for activities without lap data, which keeps it out of the top band.

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?

The purpose and the sibling contrast are front-loaded, and the long field enumeration is information-dense rather than filler. The parenthetical clarifications (units, intensity values, shared step across drill reps) each earn their place, though the run-on field list could be broken into readable groups.

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?

There is no output schema, so the description must convey return shape — and it does, listing the row-per-lap structure and every significant column with units. For a single-parameter read tool, nothing an agent needs to call it and interpret the result is missing.

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?

Only one parameter exists (activityId) and the schema documents it at 100% coverage as "Garmin activity id", so the baseline is 3. The description adds no further detail about the identifier's format or where to obtain it (e.g. from listActivities), so it does not rise above baseline.

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 names a specific resource (per-lap records of a single activity) read from the original .FIT file, and enumerates the concrete fields returned (distance, timer time, pace/speed, HR, cadence, form metrics, intensity, lap trigger, workout step). It also explicitly contrasts with getActivity, which lacks this data, so it is distinguishable from siblings without opening a 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?

It states the use case directly ("Use it for intervals and per-km splits") and names the alternative plus its limitation ("getActivity does not have them"), which tells the agent exactly when to route here versus the activity summary tool. Edge guidance on ambiguous semantics — e.g. auto laps of a free run may be labeled interval, and the reps of a drill share one step — further disambiguates interpretation.

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