Read explicit swim lengths and grouped sets

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It explicitly states that only source-aware data is returned, missing lists are reported as unavailable, and laps are never reconstructed from samples. This is highly transparent.

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 description is two sentences, front-loaded with the primary action and followed by a concise caveat. Every sentence earns its place with no unnecessary detail.

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?

Given the tool's simplicity (two parameters, no output schema, no annotations), the description covers purpose, missing-data behavior, and a key exclusion. It could benefit from mentioning the return format or structure, but overall it is sufficiently complete.

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. It adds meaning to the provider parameter by contrasting Garmin detected vs Intervals.icu auto-detected sets, and clarifies the source-aware behavior. ActivityId is not described but is self-explanatory as a common identifier.

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 uses a specific verb ('Return') and identifies the exact resource: source-aware swim lengths, plus Garmin/Intervals.icu detected sets. It distinguishes from siblings by emphasizing source-awareness and the explicit rule that laps are never reconstructed from samples, making its scope unmistakable.

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 implies when to use this tool: when provider-supplied swim lengths are needed, and when not: when reconstructed laps would be acceptable, since 'laps are never reconstructed.' It does not name specific alternatives, but the boundary is clear.

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