Build a source-aware swim progress report

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

With no annotations, the description carries the full burden. It discloses one behavioral trait (does not derive pace trends from moving time/distance), but provides no information about whether the operation is read-only, what side effects might exist, or what 'source-aware' and 'data completeness' mean in practice. This is marginally more than a minimal mention.

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 exactly two sentences, with the main purpose front-loaded and the clarifying negative statement second. Every word earns its place with no redundancy or filler.

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?

The tool has no output schema and no annotations, so the description should explain what the report returns and any edge cases. It mentions 'data completeness' but doesn't define it, nor does it describe the output format or potential errors. The core purpose is clear but the context around the report's content is incomplete.

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 add meaning. It implicitly maps 'date range' to startDate/endDate and 'pool length' to poolLengthM, but it does not explain the semantics of 'data completeness' or how the parameters interact. The parameter names are self-explanatory, but the description adds limited value beyond the schema.

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 ('Compare') and clearly identifies the resource ('Garmin swimming summaries and data completeness') and scope ('over a date range, optionally within one pool length'). The negative statement ('It does not derive pace trends...') helps distinguish it from trend-based sibling tools like cycling_progress_report or power_curve_trend.

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 the tool (comparing Garmin swimming summaries over a date range) and mentions the optional pool length filter, but it does not explicitly name alternatives or state when not to use it. The negative statement about pace trends offers a hint but no direct alternative.

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