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

The description adds behavioral context beyond the readOnlyHint annotation: it states that the tool classifies level and provides advice, which are outputs. It does not contradict the annotation (readOnlyHint=true implies no side effects, consistent). No additional behavioral details needed.

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?

Three efficient sentences: defines SWOLF, states outputs (classification, advice), and notes pool lengths. No filler; front-loaded with core purpose. Every sentence earns its place.

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 description covers inputs and outputs adequately for a calculator, but does not specify the classification scale or detail of advice. However, given no output schema, this is a minor gap. It is almost complete for the tool's complexity.

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 coverage is 100%, baseline 3. The description adds value by explaining what SWOLF means (segundos + brazadas por largo) and mentioning compatibility with 25m and 50m pools, which clarifies the metros_largo parameter. This exceeds the schema's descriptions.

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 clearly states the tool calculates SWOLF index, classifies swimmer level, and provides improvement advice. It is specific about verb (calcula) and resource (índice SWOLF and nivel del nadador), and it is distinct from sibling tools which are unrelated domains.

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?

No explicit guidance on when to use or alternatives. The usage is implied by the domain (swimming efficiency), but the description does not include exclusions or comparison with other tools, so it relies on context.

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